MPI shield
[unres4.git] / source / unres / energy.f90
index 0dbcd9c..7d21f89 100644 (file)
@@ -30,7 +30,7 @@
 ! Maximum number of SC local term fitting function coefficiants
       integer,parameter :: maxsccoef=65
 ! Maximum number of local shielding effectors
-      integer,parameter :: maxcontsshi=50
+!      integer,parameter :: maxcontsshi=50
 !-----------------------------------------------------------------------------
 ! commom.calc common/calc/
 !-----------------------------------------------------------------------------
 #ifdef MPI      
       real(kind=8) :: weights_(n_ene) !,time_Bcast,time_Bcastw
 ! shielding effect varibles for MPI
-!      real(kind=8)   fac_shieldbuf(maxres),
-!     & grad_shield_locbuf(3,maxcontsshi,-1:maxres),
-!     & grad_shield_sidebuf(3,maxcontsshi,-1:maxres),
-!     & grad_shieldbuf(3,-1:maxres)
-!       integer ishield_listbuf(maxres),
-!     &shield_listbuf(maxcontsshi,maxres)
+      real(kind=8)   fac_shieldbuf(nres), &
+      grad_shield_locbuf(3,maxcontsshi,-1:nres), &
+      grad_shield_sidebuf(3,maxcontsshi,-1:nres), &
+      grad_shieldbuf(3,-1:nres)
+       integer ishield_listbuf(nres), &
+       shield_listbuf(maxcontsshi,nres),k,j,i
 
 !      print*,"ETOTAL Processor",fg_rank," absolute rank",myrank,
 !     & " nfgtasks",nfgtasks
 ! Gay-Berne potential (shifted LJ, angular dependence).
 !  104 call egb(evdw)
        case (4)
+!       print *,"MOMO",scelemode
+        if (scelemode.eq.0) then
          call egb(evdw)
+        else
+         call emomo(evdw)
+        endif
 !      goto 107
 ! Gay-Berne-Vorobjev potential (shifted LJ, angular dependence).
 !  105 call egbv(evdw)
        if (shield_mode.eq.2) then
                  call set_shield_fac2
        endif
+      if (nfgtasks.gt.1) then
+        call MPI_Allgatherv(fac_shield(ivec_start), &
+        ivec_count(fg_rank1), &
+        MPI_DOUBLE_PRECISION,fac_shieldbuf(1),ivec_count(0), &
+        ivec_displ(0), &
+        MPI_DOUBLE_PRECISION,FG_COMM,IERROR)
+        call MPI_Allgatherv(shield_list(1,ivec_start), &
+        ivec_count(fg_rank1), &
+        MPI_I50,shield_listbuf(1,1),ivec_count(0), &
+        ivec_displ(0), &
+        MPI_I50,FG_COMM,IERROR)
+        call MPI_Allgatherv(ishield_list(ivec_start), &
+        ivec_count(fg_rank1), &
+        MPI_INTEGER,ishield_listbuf(1),ivec_count(0), &
+        ivec_displ(0), &
+        MPI_INTEGER,FG_COMM,IERROR)
+        call MPI_Allgatherv(grad_shield(1,ivec_start), &
+        ivec_count(fg_rank1), &
+        MPI_UYZ,grad_shieldbuf(1,1),ivec_count(0), &
+        ivec_displ(0), &
+        MPI_UYZ,FG_COMM,IERROR)
+        call MPI_Allgatherv(grad_shield_side(1,1,ivec_start), &
+        ivec_count(fg_rank1), &
+        MPI_SHI,grad_shield_sidebuf(1,1,1),ivec_count(0), &
+        ivec_displ(0), &
+        MPI_SHI,FG_COMM,IERROR)
+        call MPI_Allgatherv(grad_shield_loc(1,1,ivec_start), &
+        ivec_count(fg_rank1), &
+        MPI_SHI,grad_shield_locbuf(1,1,1),ivec_count(0), &
+        ivec_displ(0), &
+        MPI_SHI,FG_COMM,IERROR)
+        do i=1,nres
+         fac_shield(i)=fac_shieldbuf(i)
+         ishield_list(i)=ishield_listbuf(i)
+         do j=1,3
+         grad_shield(j,i)=grad_shieldbuf(j,i)
+         enddo !j
+         do j=1,ishield_list(i)
+           shield_list(j,i)=shield_listbuf(j,i)
+          do k=1,3
+          grad_shield_loc(k,j,i)=grad_shield_locbuf(k,j,i)
+          grad_shield_side(k,j,i)=grad_shield_sidebuf(k,j,i)
+          enddo !k
+        enddo !j
+       enddo !i
+       endif
+
+
+
+
 !       print *,"AFTER EGB",ipot,evdw
 !mc
 !mc Sep-06: egb takes care of dynamic ss bonds too
 #ifdef TIMING
       time_vec=time_vec+MPI_Wtime()-time01
 #endif
+
+
+
+
 !        print *,"Processor",myrank," left VEC_AND_DERIV"
       if (ipot.lt.6) then
 #ifdef SPLITELE
       call epep_sc_base(epepbase)
       call eprot_sc_phosphate(escpho)
       call eprot_pep_phosphate(epeppho)
+      else
+      epepbase=0.0
+      escbase=0.0
+      escpho=0.0
+      epeppho=0.0
       endif
 !      call ecatcat(ecationcation)
 !      print *,"after ebend", ebe_nucl
         if (itype(i,1).eq.ntyp1 .or. itype(i+1,1).eq.ntyp1 &
           .or. itype(i+3,1).eq.ntyp1 &
           .or. itype(i+4,1).eq.ntyp1) cycle
+!        print *,"before2",i,i+3, gshieldc_t4(2,i+3),gshieldc_t4(2,i)
         dxi=dc(1,i)
         dyi=dc(2,i)
         dzi=dc(3,i)
         call eelecij(i,i+3,ees,evdw1,eel_loc)
         if (wturn4.gt.0.0d0 .and. itype(i+2,1).ne.ntyp1) &
          call eturn4(i,eello_turn4)
+!        print *,"before",i,i+3, gshieldc_t4(2,i+3),gshieldc_t4(2,i)
         num_cont_hb(i)=num_conti
       enddo   ! i
 !
 
 !          write (iout,*) 'i',i,' j',j,' eel_loc_ij',eel_loc_ij
 !           eel_loc_ij=0.0
-          if (energy_dec) write (iout,'(a6,2i5,0pf7.3)') &
-                  'eelloc',i,j,eel_loc_ij
+!          if (energy_dec) write (iout,'(a6,2i5,0pf7.3)') &
+!                  'eelloc',i,j,eel_loc_ij
+          if (energy_dec) write (iout,'(a6,2i5,0pf7.3,8f8.3)') &
+                  'eelloc',i,j,eel_loc_ij,a22,muij(1),a23,muij(2),a32,muij(3),a33,muij(4)
+!           print *,"EELLOC",i,gel_loc_loc(i-1)
+
 !          if (energy_dec) write (iout,*) "a22",a22," a23",a23," a32",a32," a33",a33
 !          if (energy_dec) write (iout,*) "muij",muij
 !              write (iout,*) a22,muij(1),a23,muij(2),a32,muij(3)
             +aggj1(l,4)*muij(4))&
             *sss_ele_cut &
           *fac_shield(i)*fac_shield(j) &
-          *((sslipi+sslipj)/2.0d0*lipscale+1.0d0)
+         *((sslipi+sslipj)/2.0d0*lipscale+1.0d0)
 
 !+eel_loc_ij*sss_ele_grad*rmij*xtemp(l)
           enddo
       integer :: i,j,iti1,iti2,iti3,l,k,ilist,iresshield
       real(kind=8) :: eello_turn4,s1,s2,s3,zj,fracinbuf,eello_t4,&
          rlocshield
-
+      
       j=i+3
+!      if (j.ne.20) return
+!      print *,i,j,gshieldc_t4(2,j),gshieldc_t4(2,j+1)
 !CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
 !
 !               Fourth-order contributions
            iresshield=shield_list(ilist,i)
            do k=1,3
            rlocshield=grad_shield_side(k,ilist,i)*eello_t4/fac_shield(i)
+!           print *,"rlocshield",rlocshield,grad_shield_side(k,ilist,i),iresshield
            gshieldx_t4(k,iresshield)=gshieldx_t4(k,iresshield)+ &
                    rlocshield &
             +grad_shield_loc(k,ilist,i)*eello_t4/fac_shield(i)
           do ilist=1,ishield_list(j)
            iresshield=shield_list(ilist,j)
            do k=1,3
+!           print *,"rlocshieldj",j,rlocshield,grad_shield_side(k,ilist,j),iresshield
            rlocshield=grad_shield_side(k,ilist,j)*eello_t4/fac_shield(j)
            gshieldx_t4(k,iresshield)=gshieldx_t4(k,iresshield)+ &
                    rlocshield  &
            +grad_shield_loc(k,ilist,j)*eello_t4/fac_shield(j)
            gshieldc_t4(k,iresshield-1)=gshieldc_t4(k,iresshield-1) &
                   +rlocshield
+!            print *,"after", gshieldc_t4(k,iresshield-1),iresshield-1,gshieldc_t4(k,iresshield)
 
            enddo
           enddo
-
           do k=1,3
             gshieldc_t4(k,i)=gshieldc_t4(k,i)+  &
                    grad_shield(k,i)*eello_t4/fac_shield(i)
                    grad_shield(k,i)*eello_t4/fac_shield(i)
             gshieldc_t4(k,j-1)=gshieldc_t4(k,j-1)+  &
                    grad_shield(k,j)*eello_t4/fac_shield(j)
+!           print *,"gshieldc_t4(k,j+1)",j,gshieldc_t4(k,j+1)
            enddo
            endif
 
           call matmat2(ae3(1,1),e2t(1,1),ae3e2(1,1))
           call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
           s3=0.5d0*(pizda(1,1)+pizda(2,2))
+!        if (j.lt.nres-1) then
           gcorr4_turn(l,j)=gcorr4_turn(l,j)-(s1+s2+s3) &
          *fac_shield(i)*fac_shield(j)  &
          *((sslipi+sslipj)/2.0d0*lipscale+1.0d0)
-
+!        endif
 
           a_temp(1,1)=aggj1(l,1)
           a_temp(1,2)=aggj1(l,2)
           call matmat2(ae3e2(1,1),e1t(1,1),pizda(1,1))
           s3=0.5d0*(pizda(1,1)+pizda(2,2))
 !          write (iout,*) "s1",s1," s2",s2," s3",s3," s1+s2+s3",s1+s2+s3
+!        if (j.lt.nres-1) then
+!          print *,"juest before",j1, gcorr4_turn(l,j1)
           gcorr4_turn(l,j1)=gcorr4_turn(l,j1)-(s1+s2+s3) &
          *fac_shield(i)*fac_shield(j)  &
          *((sslipi+sslipj)/2.0d0*lipscale+1.0d0)
-
+!            if (shield_mode.gt.0) then
+!             print *,"juest after",j1, gcorr4_turn(l,j1),gshieldc_t4(k,j1),gshieldc_loc_t4(k,j1),gel_loc_turn4(i+2)
+!            else
+!             print *,"juest after",j1, gcorr4_turn(l,j1),gel_loc_turn4(i+2)
+!            endif
+!         endif
         enddo
          gshieldc_t4(3,i)=gshieldc_t4(3,i)+ &
           ssgradlipi*eello_t4/4.0d0*lipscale
                      wscpho*gvdwc_scpho(j,i)+   &
                      wpeppho*gvdwc_peppho(j,i)
 
-
+       
 
 
 
                      +0.5d0*(wvdwpp_nucl*gvdwpp_nucl(j,i)+welpp*gelpp(j,i)&
                      +wvdwpsb*gvdwpsb1(j,i))&
                      +wbond_nucl*gradb_nucl(j,i)+wsbloc*gsbloc(j,i)
-
+!                      if (i.eq.21) then
+!                      print *,"in sum",gradc(j,i,icg),wturn4*gcorr4_turn(j,i),&
+!                      wturn4*gshieldc_t4(j,i), &
+!                     wturn4*gshieldc_loc_t4(j,i)
+!                       endif
 !                 if ((i.le.2).and.(i.ge.1))
 !                       print *,gradc(j,i,icg),&
 !                      gradbufc(j,i),welec*gelc(j,i), &
 !              if (i.eq.3) print *,"tu?", wscpho,gvdwx_scpho(j,i)
 
         enddo
-      enddo 
+      enddo
+!#define DEBUG 
 #ifdef DEBUG
       write (iout,*) "gloc before adding corr"
       do i=1,4*nres
         write (iout,*) i,gloc(i,icg)
       enddo
 #endif
+!#undef DEBUG
 #ifdef MPI
       if (nfgtasks.gt.1) then
         do j=1,3
         endif
       endif
       endif
-!el#define DEBUG
+!#define DEBUG
 #ifdef DEBUG
       write (iout,*) "gradc gradx gloc"
       do i=1,nres
          i,(gradc(j,i,icg),j=1,3),(gradx(j,i,icg),j=1,3),gloc(i,icg)
       enddo 
 #endif
-!el#undef DEBUG
+!#undef DEBUG
 #ifdef TIMING
       time_sumgradient=time_sumgradient+MPI_Wtime()-time01
 #endif
 !      include 'COMMON.IOUNITS'
       real(kind=8), dimension(3) :: dcosom1,dcosom2
 !      print *,"wchodze"
-      eom1=eps2der*eps2rt_om1-2.0D0*alf1*eps3der+sigder*sigsq_om1
-      eom2=eps2der*eps2rt_om2+2.0D0*alf2*eps3der+sigder*sigsq_om2
+      eom1=eps2der*eps2rt_om1-2.0D0*alf1*eps3der+sigder*sigsq_om1 &
+          +dCAVdOM1+ dGCLdOM1+ dPOLdOM1
+      eom2=eps2der*eps2rt_om2+2.0D0*alf2*eps3der+sigder*sigsq_om2 &
+          +dCAVdOM2+ dGCLdOM2+ dPOLdOM2
+
       eom12=evdwij*eps1_om12+eps2der*eps2rt_om12 &
-           -2.0D0*alf12*eps3der+sigder*sigsq_om12
+           -2.0D0*alf12*eps3der+sigder*sigsq_om12&
+           +dCAVdOM12+ dGCLdOM12
 ! diagnostics only
 !      eom1=0.0d0
 !      eom2=0.0d0
           c(j,k)=c(j,k)+aincr
           c(j,k+nres)=c(j,k+nres)+aincr
           enddo
+          call zerograd
           call etotal(energia1)
           etot1=energia1(0)
         ggg(j)=(etot1-etot)/aincr
       do j=1,3
         c(j,i+nres)=c(j,i+nres)+aincr
         dc(j,i+nres)=dc(j,i+nres)+aincr
+          call zerograd
           call etotal(energia1)
           etot1=energia1(0)
         ggg(j+3)=(etot1-etot)/aincr
 !      call intcartderiv
 !      call checkintcartgrad
       call zerograd
-      aincr=1.0D-5
+      aincr=1.0D-4
       write(iout,*) 'Calling CHECK_ECARTINT.'
       nf=0
       icall=0
       write (iout,*) "split_ene ",split_ene
       call flush(iout)
       if (.not.split_ene) then
+        call zerograd
         call etotal(energia)
         etot=energia(0)
         call cartgrad
           dc(j,i+nres)=c(j,i+nres)-c(j,i)
           call int_from_cart1(.false.)
           if (.not.split_ene) then
+           call zerograd
             call etotal(energia1)
             etot1=energia1(0)
             write (iout,*) "ij",i,j," etot1",etot1
           dc(j,i+nres)=c(j,i+nres)-c(j,i)
           call int_from_cart1(.false.)
           if (.not.split_ene) then
+            call zerograd
             call etotal(energia1)
             etot2=energia1(0)
             write (iout,*) "ij",i,j," etot2",etot2
           dc(j,i+nres)=c(j,i+nres)-c(j,i)
           call int_from_cart1(.false.)
           if (.not.split_ene) then
+            call zerograd
             call etotal(energia1)
             etot1=energia1(0)
           else
           dc(j,i+nres)=c(j,i+nres)-c(j,i)
           call int_from_cart1(.false.)
           if (.not.split_ene) then
-            call etotal(energia1)
+           call zerograd
+           call etotal(energia1)
             etot2=energia1(0)
           ggg(j+3)=(etot1-etot2)/(2*aincr)
           else
         do i=1,nres
           do j=1,3
             grad_s(j,i)=gcart(j,i)
+!              if (i.eq.21) print *,"PRZEKAZANIE",gcart(j,i)
+
 !            if (i.le.2) print *,"tu?!",gcart(j,i),grad_s(j,i),gxcart(j,i)
             grad_s(j+3,i)=gxcart(j,i)
           enddo
         do i=1,nres
           do j=1,3
             grad_s(j,i)=gcart(j,i)
+!            if (i.eq.21) print *,"PRZEKAZANIE",gcart(j,i)
             grad_s(j+3,i)=gxcart(j,i)
           enddo
         enddo
 #endif
 !          call int_from_cart1(.false.)
           if (.not.split_ene) then
+           call zerograd
             call etotal(energia1)
             etot1=energia1(0)
 !            call enerprint(energia1)
           call chainbuild_cart
 !          call int_from_cart1(.false.)
           if (.not.split_ene) then
+                  call zerograd
             call etotal(energia1)
             etot2=energia1(0)
           ggg(j)=(etot1-etot2)/(2*aincr)
 !     &      dxnorm_safe(1)**2+dxnorm_safe(2)**2+dxnorm_safe(3)**2)
 !          write (iout,*)
           if (.not.split_ene) then
+            call zerograd
             call etotal(energia1)
             etot1=energia1(0)
           else
 !          write (iout,*) "dxnormnormsafe",dsqrt(
 !     &      dxnorm_safe(1)**2+dxnorm_safe(2)**2+dxnorm_safe(3)**2)
           if (.not.split_ene) then
+            call zerograd
             call etotal(energia1)
             etot2=energia1(0)
           ggg(j+3)=(etot1-etot2)/(2*aincr)
           eel_loc_ij=a22*muij(1)+a23*muij(2)+a32*muij(3) &
            +a33*muij(4)
 !          write (iout,*) 'i',i,' j',j,' eel_loc_ij',eel_loc_ij
-
+!           print *,"EELLOC",i,gel_loc_loc(i-1)
           if (energy_dec) write (iout,'(a6,2i5,0pf7.3)') &
                   'eelloc',i,j,eel_loc_ij
 !              write (iout,*) a22,muij(1),a23,muij(2),a32,muij(3) !d
 ! This subrouting calculates total Cartesian coordinate gradient. 
 ! The subroutine chainbuild_cart and energy MUST be called beforehand.
 !
-#define DEBUG
+!#define DEBUG
 #ifdef TIMING
       time00=MPI_Wtime()
 #endif
       call sum_gradient
 #ifdef TIMING
 #endif
+!#define DEBUG
 !el      write (iout,*) "After sum_gradient"
 #ifdef DEBUG
 !el      write (iout,*) "After sum_gradient"
         write (iout,*) i," gradx  ",(gradx(j,i,icg),j=1,3)
       enddo
 #endif
+!#undef DEBUG
 ! If performing constraint dynamics, add the gradients of the constraint energy
       if(usampl.and.totT.gt.eq_time) then
          do i=1,nct
 #endif
 !     call checkintcartgrad
 !     write(iout,*) 'calling int_to_cart'
+!#define DEBUG
 #ifdef DEBUG
       write (iout,*) "gcart, gxcart, gloc before int_to_cart"
 #endif
                 (gxcart(j,i),j=1,3)
             enddo
 #endif
+!#undef DEBUG
 #ifdef CARGRAD
 #ifdef DEBUG
             write (iout,*) "CARGRAD"
 #ifdef TIMING
             time_cartgrad=time_cartgrad+MPI_Wtime()-time00
 #endif
-#undef DEBUG
+!#undef DEBUG
             return
             end subroutine cartgrad
       !-----------------------------------------------------------------------------
               dcosomicron(j,1,1,i)=-(dc_norm(j,i-1+nres)+ &
               cost1*dc_norm(j,i-2))/ &
               vbld(i-1)
-              domicron(j,1,1,i)=-1/sint1*dcosomicron(j,1,1,i)
+              domicron(j,1,1,i)=-1.0/sint1*dcosomicron(j,1,1,i)
               dcosomicron(j,1,2,i)=-(dc_norm(j,i-2) &
               +cost1*(dc_norm(j,i-1+nres)))/ &
               vbld(i-1+nres)
-              domicron(j,1,2,i)=-1/sint1*dcosomicron(j,1,2,i)
+              domicron(j,1,2,i)=-1.0/sint1*dcosomicron(j,1,2,i)
       !C Calculate derivative over second omicron Sci-1,Cai-1 Cai
       !C Looks messy but better than if in loop
               dcosomicron(j,2,1,i)=-(-dc_norm(j,i-1+nres) &
               +cost2*dc_norm(j,i-1))/ &
               vbld(i)
-              domicron(j,2,1,i)=-1/sint2*dcosomicron(j,2,1,i)
+              domicron(j,2,1,i)=-1.0/sint2*dcosomicron(j,2,1,i)
               dcosomicron(j,2,2,i)=-(dc_norm(j,i-1) &
                +cost2*(-dc_norm(j,i-1+nres)))/ &
               vbld(i-1+nres)
       !          write(iout,*) "vbld", i,itype(i,1),vbld(i-1+nres)
-              domicron(j,2,2,i)=-1/sint2*dcosomicron(j,2,2,i)
+              domicron(j,2,2,i)=-1.0/sint2*dcosomicron(j,2,2,i)
             enddo
              endif
             enddo
                dcosphi(j,1,i)=fac1*dcostheta(j,1,i-1)+fac3* &
                dcostheta(j,1,i-1)-fac0*(dc_norm(j,i-1)-scalp* &
                dc_norm(j,i-3))/vbld(i-2)
-               dphi(j,1,i)=-1/sing*dcosphi(j,1,i)       
+               dphi(j,1,i)=-1.0/sing*dcosphi(j,1,i)       
                dcosphi(j,2,i)=fac1*dcostheta(j,2,i-1)+fac2* &
                dcostheta(j,1,i)+fac3*dcostheta(j,2,i-1)+fac4* &
                dcostheta(j,1,i)
-               dphi(j,2,i)=-1/sing*dcosphi(j,2,i)      
+               dphi(j,2,i)=-1.0/sing*dcosphi(j,2,i)      
                dcosphi(j,3,i)=fac2*dcostheta(j,2,i)+fac4* &
                dcostheta(j,2,i)-fac0*(dc_norm(j,i-3)-scalp* &
                dc_norm(j,i-1))/vbld(i)
-               dphi(j,3,i)=-1/sing*dcosphi(j,3,i)       
+               dphi(j,3,i)=-1.0/sing*dcosphi(j,3,i)       
+!#define DEBUG
+#ifdef DEBUG
+               write(iout,*) "just after",dphi(j,3,i),sing,dcosphi(j,3,i)
+#endif
+!#undef DEBUG
                endif
              enddo
             endif                                                                                                         
             call MPI_Gatherv(dtheta(1,1,ithet_start),ithet_count(fg_rank),&
             MPI_THET,dtheta(1,1,1),ithet_count(0),ithet_displ(0),MPI_THET,&
             king,FG_COMM,IERROR)
+!#define DEBUG
 #ifdef DEBUG
       !d      write (iout,*) "Gather dphi"
       !d      call flush(iout)
             write (iout,'(i3,3(3f8.5,3x))') i,((dphi(j,k,i),k=1,3),j=1,3)
             enddo
 #endif
+!#undef DEBUG
             call MPI_Gatherv(dphi(1,1,iphi1_start),iphi1_count(fg_rank),&
             MPI_GAM,dphi(1,1,1),iphi1_count(0),iphi1_displ(0),MPI_GAM,&
             king,FG_COMM,IERROR)
 #endif
             endif
 #endif
+!#define DEBUG
 #ifdef DEBUG
             write (iout,*) "dtheta after gather"
             do i=1,nres
             write (iout,'(i3,3(3f8.5,3x))') i,((domega(j,k,i),j=1,3),k=1,3)
             enddo
 #endif
+!#undef DEBUG
             return
             end subroutine intcartderiv
       !-----------------------------------------------------------------------------
       enddo
 !C now sscale fraction
        sh_frac_dist=-(dist_pep_side-rpp(1,1)-buff_shield)/buff_shield
-!C       print *,buff_shield,"buff"
+!       print *,buff_shield,"buff",sh_frac_dist
 !C now sscale
         if (sh_frac_dist.le.0.0) cycle
 !C        print *,ishield_list(i),i
       long=long_r_sidechain(itype(k,1))
       costhet=1.0d0/dsqrt(1.0d0+short**2/dist_pep_side**2)
       sinthet=short/dist_pep_side*costhet
+!      print *,"SORT",short,long,sinthet,costhet
 !C now costhet_grad
 !C       costhet=0.6d0
 !C       sinthet=0.8
        enddo
 !C      print *,sinphi,sinthet
       VofOverlap=VSolvSphere/2.0d0*(1.0d0-dsqrt(1.0d0-sinphi*sinthet)) &
-     &                    /VSolvSphere_div
+                         /VSolvSphere_div
 !C     &                    *wshield
 !C now the gradient...
       do j=1,3
             sinphi/sinthet*costhet*costhet_grad(j)&
            +sinthet/sinphi*cosphi*cosphi_grad_long(j))) &
             )*wshield
-
+!       print *, 1.0d0/(-dsqrt(1.0d0-sinphi*sinthet)),&
+!            sinphi/sinthet,&
+!           +sinthet/sinphi,"HERE"
        grad_shield_loc(j,ishield_list(i),i)=   &
             scale_fac_dist*VSolvSphere/VSolvSphere_div/2.0d0*&
       (1.0d0/(dsqrt(1.0d0-sinphi*sinthet))*(&
             sinthet/sinphi*cosphi*cosphi_grad_loc(j)&
              ))&
              *wshield
+!         print *,grad_shield_loc(j,ishield_list(i),i)
       enddo
       VolumeTotal=VolumeTotal+VofOverlap*scale_fac_dist
       enddo
       fac_shield(i)=VolumeTotal*wshield+(1.0d0-wshield)
      
-!C      write(2,*) "TOTAL VOLUME",i,itype(i,1),fac_shield(i)
+!      write(2,*) "TOTAL VOLUME",i,itype(i,1),fac_shield(i)
       enddo
       return
       end subroutine set_shield_fac2
           dscj_inv = vbld_inv(j+1)/2.0
 ! Gay-berne var's
           sig0ij = sigma_peppho
-          chi1=0.0d0
-          chi2=0.0d0
+!          chi1=0.0d0
+!          chi2=0.0d0
           chi12  = chi1 * chi2
-          chip1=0.0d0
-          chip2=0.0d0
+!          chip1=0.0d0
+!          chip2=0.0d0
           chip12 = chip1 * chip2
-          chis1 = 0.0d0
-          chis2 = 0.0d0
+!          chis1 = 0.0d0
+!          chis2 = 0.0d0
           chis12 = chis1 * chis2
           sig1 = sigmap1_peppho
           sig2 = sigmap2_peppho
        enddo
        enddo
       end subroutine eprot_pep_phosphate
+!!!!!!!!!!!!!!!!-------------------------------------------------------------
+      subroutine emomo(evdw)
+      use calc_data
+      use comm_momo
+!      implicit real*8 (a-h,o-z)
+!      include 'DIMENSIONS'
+!      include 'COMMON.GEO'
+!      include 'COMMON.VAR'
+!      include 'COMMON.LOCAL'
+!      include 'COMMON.CHAIN'
+!      include 'COMMON.DERIV'
+!      include 'COMMON.NAMES'
+!      include 'COMMON.INTERACT'
+!      include 'COMMON.IOUNITS'
+!      include 'COMMON.CALC'
+!      include 'COMMON.CONTROL'
+!      include 'COMMON.SBRIDGE'
+      logical :: lprn
+!el local variables
+      integer :: iint,itypi1,subchap,isel
+      real(kind=8) :: rrij,xi,yi,zi,sig,rij_shift,e1,e2,sigm,epsi
+      real(kind=8) :: evdw
+      real(kind=8) :: xj_safe,yj_safe,zj_safe,xj_temp,yj_temp,zj_temp,&
+                    dist_temp, dist_init,ssgradlipi,ssgradlipj, &
+                    sslipi,sslipj,faclip,alpha_sco
+      integer :: ii
+      real(kind=8) :: fracinbuf
+       real (kind=8) :: escpho
+       real (kind=8),dimension(4):: ener
+       real(kind=8) :: b1,b2,egb
+       real(kind=8) :: Fisocav,ECL,Elj,Equad,Epol,eheadtail,&
+        Lambf,&
+        Chif,ChiLambf,Fcav,dFdR,dFdOM1,&
+        dFdOM2,dFdL,dFdOM12,&
+        federmaus,&
+        d1i,d1j
+!       real(kind=8),dimension(3,2)::erhead_tail
+!       real(kind=8),dimension(3) :: Rhead_distance,ertail,erhead,Rtail_distance
+       real(kind=8) ::  facd4, adler, Fgb, facd3
+       integer troll,jj,istate
+       real (kind=8) :: dcosom1(3),dcosom2(3)
+       eps_out=80.0d0
+       sss_ele_cut=1.0d0
+!       print *,"EVDW KURW",evdw,nres
+      do i=iatsc_s,iatsc_e
+!        print *,"I am in EVDW",i
+        itypi=iabs(itype(i,1))
+!        if (i.ne.47) cycle
+        if (itypi.eq.ntyp1) cycle
+        itypi1=iabs(itype(i+1,1))
+        xi=c(1,nres+i)
+        yi=c(2,nres+i)
+        zi=c(3,nres+i)
+          xi=dmod(xi,boxxsize)
+          if (xi.lt.0) xi=xi+boxxsize
+          yi=dmod(yi,boxysize)
+          if (yi.lt.0) yi=yi+boxysize
+          zi=dmod(zi,boxzsize)
+          if (zi.lt.0) zi=zi+boxzsize
+
+       if ((zi.gt.bordlipbot)  &
+        .and.(zi.lt.bordliptop)) then
+!C the energy transfer exist
+        if (zi.lt.buflipbot) then
+!C what fraction I am in
+         fracinbuf=1.0d0-  &
+              ((zi-bordlipbot)/lipbufthick)
+!C lipbufthick is thickenes of lipid buffore
+         sslipi=sscalelip(fracinbuf)
+         ssgradlipi=-sscagradlip(fracinbuf)/lipbufthick
+        elseif (zi.gt.bufliptop) then
+         fracinbuf=1.0d0-((bordliptop-zi)/lipbufthick)
+         sslipi=sscalelip(fracinbuf)
+         ssgradlipi=sscagradlip(fracinbuf)/lipbufthick
+        else
+         sslipi=1.0d0
+         ssgradlipi=0.0
+        endif
+       else
+         sslipi=0.0d0
+         ssgradlipi=0.0
+       endif
+!       print *, sslipi,ssgradlipi
+        dxi=dc_norm(1,nres+i)
+        dyi=dc_norm(2,nres+i)
+        dzi=dc_norm(3,nres+i)
+!        dsci_inv=dsc_inv(itypi)
+        dsci_inv=vbld_inv(i+nres)
+!       write (iout,*) "i",i,dsc_inv(itypi),dsci_inv,1.0d0/vbld(i+nres)
+!       write (iout,*) "dcnori",dxi*dxi+dyi*dyi+dzi*dzi
+!
+! Calculate SC interaction energy.
+!
+        do iint=1,nint_gr(i)
+          do j=istart(i,iint),iend(i,iint)
+!             print *,"JA PIER",i,j,iint,istart(i,iint),iend(i,iint)
+            IF (dyn_ss_mask(i).and.dyn_ss_mask(j)) THEN
+              call dyn_ssbond_ene(i,j,evdwij)
+              evdw=evdw+evdwij
+              if (energy_dec) write (iout,'(a6,2i5,0pf7.3,a3)') &
+                              'evdw',i,j,evdwij,' ss'
+!              if (energy_dec) write (iout,*) &
+!                              'evdw',i,j,evdwij,' ss'
+             do k=j+1,iend(i,iint)
+!C search over all next residues
+              if (dyn_ss_mask(k)) then
+!C check if they are cysteins
+!C              write(iout,*) 'k=',k
+
+!c              write(iout,*) "PRZED TRI", evdwij
+!               evdwij_przed_tri=evdwij
+              call triple_ssbond_ene(i,j,k,evdwij)
+!c               if(evdwij_przed_tri.ne.evdwij) then
+!c                 write (iout,*) "TRI:", evdwij, evdwij_przed_tri
+!c               endif
+
+!c              write(iout,*) "PO TRI", evdwij
+!C call the energy function that removes the artifical triple disulfide
+!C bond the soubroutine is located in ssMD.F
+              evdw=evdw+evdwij
+              if (energy_dec) write (iout,'(a6,2i5,0pf7.3,a3)') &
+                            'evdw',i,j,evdwij,'tss'
+              endif!dyn_ss_mask(k)
+             enddo! k
+            ELSE
+!el            ind=ind+1
+            itypj=iabs(itype(j,1))
+            if (itypj.eq.ntyp1) cycle
+             CALL elgrad_init(eheadtail,Egb,Ecl,Elj,Equad,Epol)
+
+!             if (j.ne.78) cycle
+!            dscj_inv=dsc_inv(itypj)
+            dscj_inv=vbld_inv(j+nres)
+           xj=c(1,j+nres)
+           yj=c(2,j+nres)
+           zj=c(3,j+nres)
+           xj=dmod(xj,boxxsize)
+           if (xj.lt.0) xj=xj+boxxsize
+           yj=dmod(yj,boxysize)
+           if (yj.lt.0) yj=yj+boxysize
+           zj=dmod(zj,boxzsize)
+           if (zj.lt.0) zj=zj+boxzsize
+          dist_init=(xj-xi)**2+(yj-yi)**2+(zj-zi)**2
+          xj_safe=xj
+          yj_safe=yj
+          zj_safe=zj
+          subchap=0
+
+          do xshift=-1,1
+          do yshift=-1,1
+          do zshift=-1,1
+          xj=xj_safe+xshift*boxxsize
+          yj=yj_safe+yshift*boxysize
+          zj=zj_safe+zshift*boxzsize
+          dist_temp=(xj-xi)**2+(yj-yi)**2+(zj-zi)**2
+          if(dist_temp.lt.dist_init) then
+            dist_init=dist_temp
+            xj_temp=xj
+            yj_temp=yj
+            zj_temp=zj
+            subchap=1
+          endif
+          enddo
+          enddo
+          enddo
+          if (subchap.eq.1) then
+          xj=xj_temp-xi
+          yj=yj_temp-yi
+          zj=zj_temp-zi
+          else
+          xj=xj_safe-xi
+          yj=yj_safe-yi
+          zj=zj_safe-zi
+          endif
+          dxj = dc_norm( 1, nres+j )
+          dyj = dc_norm( 2, nres+j )
+          dzj = dc_norm( 3, nres+j )
+!          print *,i,j,itypi,itypj
+!          d1i=0.0d0
+!          d1j=0.0d0
+!          BetaT = 1.0d0 / (298.0d0 * Rb)
+! Gay-berne var's
+!1!          sig0ij = sigma_scsc( itypi,itypj )
+!          chi1=0.0d0
+!          chi2=0.0d0
+!          chip1=0.0d0
+!          chip2=0.0d0
+! not used by momo potential, but needed by sc_angular which is shared
+! by all energy_potential subroutines
+          alf1   = 0.0d0
+          alf2   = 0.0d0
+          alf12  = 0.0d0
+          a12sq = rborn(itypi,itypj) * rborn(itypj,itypi)
+!       a12sq = a12sq * a12sq
+! charge of amino acid itypi is...
+          chis1 = chis(itypi,itypj)
+          chis2 = chis(itypj,itypi)
+          chis12 = chis1 * chis2
+          sig1 = sigmap1(itypi,itypj)
+          sig2 = sigmap2(itypi,itypj)
+!       write (*,*) "sig1 = ", sig1
+!          chis1=0.0
+!          chis2=0.0
+!                    chis12 = chis1 * chis2
+!          sig1=0.0
+!          sig2=0.0
+!       write (*,*) "sig2 = ", sig2
+! alpha factors from Fcav/Gcav
+          b1cav = alphasur(1,itypi,itypj)
+!          b1cav=0.0d0
+          b2cav = alphasur(2,itypi,itypj)
+          b3cav = alphasur(3,itypi,itypj)
+          b4cav = alphasur(4,itypi,itypj)
+! used to determine whether we want to do quadrupole calculations
+       eps_in = epsintab(itypi,itypj)
+       if (eps_in.eq.0.0) eps_in=1.0
+         
+       eps_inout_fac = ( (1.0d0/eps_in) - (1.0d0/eps_out))
+       Rtail = 0.0d0
+!       dtail(1,itypi,itypj)=0.0
+!       dtail(2,itypi,itypj)=0.0
+
+       DO k = 1, 3
+        ctail(k,1)=c(k,i+nres)-dtail(1,itypi,itypj)*dc_norm(k,nres+i)
+        ctail(k,2)=c(k,j+nres)-dtail(2,itypi,itypj)*dc_norm(k,nres+j)
+       END DO
+!c! tail distances will be themselves usefull elswhere
+!c1 (in Gcav, for example)
+       Rtail_distance(1) = ctail( 1, 2 ) - ctail( 1,1 )
+       Rtail_distance(2) = ctail( 2, 2 ) - ctail( 2,1 )
+       Rtail_distance(3) = ctail( 3, 2 ) - ctail( 3,1 )
+       Rtail = dsqrt( &
+          (Rtail_distance(1)*Rtail_distance(1)) &
+        + (Rtail_distance(2)*Rtail_distance(2)) &
+        + (Rtail_distance(3)*Rtail_distance(3))) 
+
+!       write (*,*) "eps_inout_fac = ", eps_inout_fac
+!-------------------------------------------------------------------
+! tail location and distance calculations
+       d1 = dhead(1, 1, itypi, itypj)
+       d2 = dhead(2, 1, itypi, itypj)
+
+       DO k = 1,3
+! location of polar head is computed by taking hydrophobic centre
+! and moving by a d1 * dc_norm vector
+! see unres publications for very informative images
+        chead(k,1) = c(k, i+nres) + d1 * dc_norm(k, i+nres)
+        chead(k,2) = c(k, j+nres) + d2 * dc_norm(k, j+nres)
+! distance 
+!        Rsc_distance(k) = dabs(c(k, i+nres) - c(k, j+nres))
+!        Rsc(k) = Rsc_distance(k) * Rsc_distance(k)
+        Rhead_distance(k) = chead(k,2) - chead(k,1)
+       END DO
+! pitagoras (root of sum of squares)
+       Rhead = dsqrt( &
+          (Rhead_distance(1)*Rhead_distance(1)) &
+        + (Rhead_distance(2)*Rhead_distance(2)) &
+        + (Rhead_distance(3)*Rhead_distance(3)))
+!-------------------------------------------------------------------
+! zero everything that should be zero'ed
+       evdwij = 0.0d0
+       ECL = 0.0d0
+       Elj = 0.0d0
+       Equad = 0.0d0
+       Epol = 0.0d0
+       Fcav=0.0d0
+       eheadtail = 0.0d0
+       dGCLdOM1 = 0.0d0
+       dGCLdOM2 = 0.0d0
+       dGCLdOM12 = 0.0d0
+       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = 0.0d0
+          Fcav = 0.0d0
+          dFdR = 0.0d0
+          dCAVdOM1  = 0.0d0
+          dCAVdOM2  = 0.0d0
+          dCAVdOM12 = 0.0d0
+          dscj_inv = vbld_inv(j+nres)
+!          print *,i,j,dscj_inv,dsci_inv
+! rij holds 1/(distance of Calpha atoms)
+          rrij = 1.0D0 / ( xj*xj + yj*yj + zj*zj)
+          rij  = dsqrt(rrij)
+!----------------------------
+          CALL sc_angular
+! this should be in elgrad_init but om's are calculated by sc_angular
+! which in turn is used by older potentials
+! om = omega, sqom = om^2
+          sqom1  = om1 * om1
+          sqom2  = om2 * om2
+          sqom12 = om12 * om12
+
+! now we calculate EGB - Gey-Berne
+! It will be summed up in evdwij and saved in evdw
+          sigsq     = 1.0D0  / sigsq
+          sig       = sig0ij * dsqrt(sigsq)
+!          rij_shift = 1.0D0  / rij - sig + sig0ij
+          rij_shift = Rtail - sig + sig0ij
+          IF (rij_shift.le.0.0D0) THEN
+           evdw = 1.0D20
+           RETURN
+          END IF
+          sigder = -sig * sigsq
+          rij_shift = 1.0D0 / rij_shift
+          fac       = rij_shift**expon
+          c1        = fac  * fac * aa_aq(itypi,itypj)
+!          print *,"ADAM",aa_aq(itypi,itypj)
+
+!          c1        = 0.0d0
+          c2        = fac  * bb_aq(itypi,itypj)
+!          c2        = 0.0d0
+          evdwij    = eps1 * eps2rt * eps3rt * ( c1 + c2 )
+          eps2der   = eps3rt * evdwij
+          eps3der   = eps2rt * evdwij
+!          evdwij    = 4.0d0 * eps2rt * eps3rt * evdwij
+          evdwij    = eps2rt * eps3rt * evdwij
+!#ifdef TSCSC
+!          IF (bb_aq(itypi,itypj).gt.0) THEN
+!           evdw_p = evdw_p + evdwij
+!          ELSE
+!           evdw_m = evdw_m + evdwij
+!          END IF
+!#else
+          evdw = evdw  &
+              + evdwij
+!#endif
+
+          c1     = c1 * eps1 * eps2rt**2 * eps3rt**2
+          fac    = -expon * (c1 + evdwij) * rij_shift
+          sigder = fac * sigder
+!          fac    = rij * fac
+! Calculate distance derivative
+          gg(1) =  fac
+          gg(2) =  fac
+          gg(3) =  fac
+!          if (b2.gt.0.0) then
+          fac = chis1 * sqom1 + chis2 * sqom2 &
+          - 2.0d0 * chis12 * om1 * om2 * om12
+! we will use pom later in Gcav, so dont mess with it!
+          pom = 1.0d0 - chis1 * chis2 * sqom12
+          Lambf = (1.0d0 - (fac / pom))
+!          print *,"fac,pom",fac,pom,Lambf
+          Lambf = dsqrt(Lambf)
+          sparrow = 1.0d0 / dsqrt(sig1**2.0d0 + sig2**2.0d0)
+!          print *,"sig1,sig2",sig1,sig2,itypi,itypj
+!       write (*,*) "sparrow = ", sparrow
+          Chif = Rtail * sparrow
+!           print *,"rij,sparrow",rij , sparrow 
+          ChiLambf = Chif * Lambf
+          eagle = dsqrt(ChiLambf)
+          bat = ChiLambf ** 11.0d0
+          top = b1cav * ( eagle + b2cav * ChiLambf - b3cav )
+          bot = 1.0d0 + b4cav * (ChiLambf ** 12.0d0)
+          botsq = bot * bot
+!          print *,top,bot,"bot,top",ChiLambf,Chif
+          Fcav = top / bot
+
+       dtop = b1cav * ((Lambf / (2.0d0 * eagle)) + (b2cav * Lambf))
+       dbot = 12.0d0 * b4cav * bat * Lambf
+       dFdR = ((dtop * bot - top * dbot) / botsq) * sparrow
+
+          dtop = b1cav * ((Chif / (2.0d0 * eagle)) + (b2cav * Chif))
+          dbot = 12.0d0 * b4cav * bat * Chif
+          eagle = Lambf * pom
+          dFdOM1  = -(chis1 * om1 - chis12 * om2 * om12) / (eagle)
+          dFdOM2  = -(chis2 * om2 - chis12 * om1 * om12) / (eagle)
+          dFdOM12 = chis12 * (chis1 * om1 * om12 - om2) &
+              * (chis2 * om2 * om12 - om1) / (eagle * pom)
+
+          dFdL = ((dtop * bot - top * dbot) / botsq)
+!       dFdL = 0.0d0
+          dCAVdOM1  = dFdL * ( dFdOM1 )
+          dCAVdOM2  = dFdL * ( dFdOM2 )
+          dCAVdOM12 = dFdL * ( dFdOM12 )
+
+       DO k= 1, 3
+        ertail(k) = Rtail_distance(k)/Rtail
+       END DO
+       erdxi = scalar( ertail(1), dC_norm(1,i+nres) )
+       erdxj = scalar( ertail(1), dC_norm(1,j+nres) )
+       facd1 = dtail(1,itypi,itypj) * vbld_inv(i+nres)
+       facd2 = dtail(2,itypi,itypj) * vbld_inv(j+nres)
+       DO k = 1, 3
+!c!      write (*,*) "Gvdwc(",k,",",i,")=", gvdwc(k,i)
+!c!      write (*,*) "Gvdwc(",k,",",j,")=", gvdwc(k,j)
+        pom = ertail(k)-facd1*(ertail(k)-erdxi*dC_norm(k,i+nres))
+        gvdwx(k,i) = gvdwx(k,i) &
+                  - (( dFdR + gg(k) ) * pom)
+!c!     &             - ( dFdR * pom )
+        pom = ertail(k)-facd2*(ertail(k)-erdxj*dC_norm(k,j+nres))
+        gvdwx(k,j) = gvdwx(k,j)   &
+                  + (( dFdR + gg(k) ) * pom)
+!c!     &             + ( dFdR * pom )
+
+        gvdwc(k,i) = gvdwc(k,i)  &
+                  - (( dFdR + gg(k) ) * ertail(k))
+!c!     &             - ( dFdR * ertail(k))
+
+        gvdwc(k,j) = gvdwc(k,j) &
+                  + (( dFdR + gg(k) ) * ertail(k))
+!c!     &             + ( dFdR * ertail(k))
+
+        gg(k) = 0.0d0
+!      write (*,*) "Gvdwc(",k,",",i,")=", gvdwc(k,i)
+!      write (*,*) "Gvdwc(",k,",",j,")=", gvdwc(k,j)
+      END DO
+
+
+!c! Compute head-head and head-tail energies for each state
+
+          isel = iabs(Qi) + iabs(Qj)
+!          isel=0
+          IF (isel.eq.0) THEN
+!c! No charges - do nothing
+           eheadtail = 0.0d0
+
+          ELSE IF (isel.eq.4) THEN
+!c! Calculate dipole-dipole interactions
+           CALL edd(ecl)
+           eheadtail = ECL
+!           eheadtail = 0.0d0
+
+          ELSE IF (isel.eq.1 .and. iabs(Qi).eq.1) THEN
+!c! Charge-nonpolar interactions
+           CALL eqn(epol)
+           eheadtail = epol
+!           eheadtail = 0.0d0
+
+          ELSE IF (isel.eq.1 .and. iabs(Qj).eq.1) THEN
+!c! Nonpolar-charge interactions
+           CALL enq(epol)
+           eheadtail = epol
+!           eheadtail = 0.0d0
+
+          ELSE IF (isel.eq.3 .and. icharge(itypj).eq.2) THEN
+!c! Charge-dipole interactions
+           CALL eqd(ecl, elj, epol)
+           eheadtail = ECL + elj + epol
+!           eheadtail = 0.0d0
+
+          ELSE IF (isel.eq.3 .and. icharge(itypi).eq.2) THEN
+!c! Dipole-charge interactions
+           CALL edq(ecl, elj, epol)
+          eheadtail = ECL + elj + epol
+!           eheadtail = 0.0d0
+
+          ELSE IF ((isel.eq.2.and.   &
+               iabs(Qi).eq.1).and.  &
+               nstate(itypi,itypj).eq.1) THEN
+!c! Same charge-charge interaction ( +/+ or -/- )
+           CALL eqq(Ecl,Egb,Epol,Fisocav,Elj)
+           eheadtail = ECL + Egb + Epol + Fisocav + Elj
+!           eheadtail = 0.0d0
+
+          ELSE IF ((isel.eq.2.and.  &
+               iabs(Qi).eq.1).and. &
+               nstate(itypi,itypj).ne.1) THEN
+!c! Different charge-charge interaction ( +/- or -/+ )
+           CALL energy_quad(istate,eheadtail,Ecl,Egb,Epol,Fisocav,Elj,Equad)
+          END IF
+       END IF  ! this endif ends the "catch the gly-gly" at the beggining of Fcav
+      evdw = evdw  + Fcav + eheadtail
+
+       IF (energy_dec) write (iout,'(2(1x,a3,i3),3f6.2,10f16.7)') &
+        restyp(itype(i,1),1),i,restyp(itype(j,1),1),j,&
+        1.0d0/rij,Rtail,Rhead,evdwij,Fcav,Ecl,Egb,Epol,Fisocav,Elj,&
+        Equad,evdwij+Fcav+eheadtail,evdw
+!       evdw = evdw  + Fcav  + eheadtail
+
+        iF (nstate(itypi,itypj).eq.1) THEN
+        CALL sc_grad
+       END IF
+!c!-------------------------------------------------------------------
+!c! NAPISY KONCOWE
+         END DO   ! j
+        END DO    ! iint
+       END DO     ! i
+!c      write (iout,*) "Number of loop steps in EGB:",ind
+!c      energy_dec=.false.
+!              print *,"EVDW KURW",evdw,nres
+
+       RETURN
+      END SUBROUTINE emomo
+!C------------------------------------------------------------------------------------
+      SUBROUTINE eqq(Ecl,Egb,Epol,Fisocav,Elj)
+      use calc_data
+      use comm_momo
+       real (kind=8) ::  facd3, facd4, federmaus, adler,&
+         Ecl,Egb,Epol,Fisocav,Elj,Fgb
+!       integer :: k
+!c! Epol and Gpol analytical parameters
+       alphapol1 = alphapol(itypi,itypj)
+       alphapol2 = alphapol(itypj,itypi)
+!c! Fisocav and Gisocav analytical parameters
+       al1  = alphiso(1,itypi,itypj)
+       al2  = alphiso(2,itypi,itypj)
+       al3  = alphiso(3,itypi,itypj)
+       al4  = alphiso(4,itypi,itypj)
+       csig = (1.0d0  &
+           / dsqrt(sigiso1(itypi, itypj)**2.0d0 &
+           + sigiso2(itypi,itypj)**2.0d0))
+!c!
+       pis  = sig0head(itypi,itypj)
+       eps_head = epshead(itypi,itypj)
+       Rhead_sq = Rhead * Rhead
+!c! R1 - distance between head of ith side chain and tail of jth sidechain
+!c! R2 - distance between head of jth side chain and tail of ith sidechain
+       R1 = 0.0d0
+       R2 = 0.0d0
+       DO k = 1, 3
+!c! Calculate head-to-tail distances needed by Epol
+        R1=R1+(ctail(k,2)-chead(k,1))**2
+        R2=R2+(chead(k,2)-ctail(k,1))**2
+       END DO
+!c! Pitagoras
+       R1 = dsqrt(R1)
+       R2 = dsqrt(R2)
+
+!c!      R1     = dsqrt((Rtail**2)+((dtail(1,itypi,itypj)
+!c!     &        +dhead(1,1,itypi,itypj))**2))
+!c!      R2     = dsqrt((Rtail**2)+((dtail(2,itypi,itypj)
+!c!     &        +dhead(2,1,itypi,itypj))**2))
+
+!c!-------------------------------------------------------------------
+!c! Coulomb electrostatic interaction
+       Ecl = (332.0d0 * Qij) / Rhead
+!c! derivative of Ecl is Gcl...
+       dGCLdR = (-332.0d0 * Qij ) / Rhead_sq
+       dGCLdOM1 = 0.0d0
+       dGCLdOM2 = 0.0d0
+       dGCLdOM12 = 0.0d0
+       ee0 = dexp(-( Rhead_sq ) / (4.0d0 * a12sq))
+       Fgb = sqrt( ( Rhead_sq ) + a12sq * ee0)
+       Egb = -(332.0d0 * Qij * eps_inout_fac) / Fgb
+!       print *,"EGB WTF",Qij,eps_inout_fac,Fgb,itypi,itypj,eps_in,eps_out
+!c! Derivative of Egb is Ggb...
+       dGGBdFGB = -(-332.0d0 * Qij * eps_inout_fac) / (Fgb * Fgb)
+       dFGBdR = ( Rhead * ( 2.0d0 - (0.5d0 * ee0) ) )/ ( 2.0d0 * Fgb )
+       dGGBdR = dGGBdFGB * dFGBdR
+!c!-------------------------------------------------------------------
+!c! Fisocav - isotropic cavity creation term
+!c! or "how much energy it costs to put charged head in water"
+       pom = Rhead * csig
+       top = al1 * (dsqrt(pom) + al2 * pom - al3)
+       bot = (1.0d0 + al4 * pom**12.0d0)
+       botsq = bot * bot
+       FisoCav = top / bot
+!      write (*,*) "Rhead = ",Rhead
+!      write (*,*) "csig = ",csig
+!      write (*,*) "pom = ",pom
+!      write (*,*) "al1 = ",al1
+!      write (*,*) "al2 = ",al2
+!      write (*,*) "al3 = ",al3
+!      write (*,*) "al4 = ",al4
+!        write (*,*) "top = ",top
+!        write (*,*) "bot = ",bot
+!c! Derivative of Fisocav is GCV...
+       dtop = al1 * ((1.0d0 / (2.0d0 * dsqrt(pom))) + al2)
+       dbot = 12.0d0 * al4 * pom ** 11.0d0
+       dGCVdR = ((dtop * bot - top * dbot) / botsq) * csig
+!c!-------------------------------------------------------------------
+!c! Epol
+!c! Polarization energy - charged heads polarize hydrophobic "neck"
+       MomoFac1 = (1.0d0 - chi1 * sqom2)
+       MomoFac2 = (1.0d0 - chi2 * sqom1)
+       RR1  = ( R1 * R1 ) / MomoFac1
+       RR2  = ( R2 * R2 ) / MomoFac2
+       ee1  = exp(-( RR1 / (4.0d0 * a12sq) ))
+       ee2  = exp(-( RR2 / (4.0d0 * a12sq) ))
+       fgb1 = sqrt( RR1 + a12sq * ee1 )
+       fgb2 = sqrt( RR2 + a12sq * ee2 )
+       epol = 332.0d0 * eps_inout_fac * ( &
+      (( alphapol1 / fgb1 )**4.0d0)+((alphapol2/fgb2) ** 4.0d0 ))
+!c!       epol = 0.0d0
+       dPOLdFGB1 = -(1328.0d0 * eps_inout_fac * alphapol1 ** 4.0d0)&
+               / (fgb1 ** 5.0d0)
+       dPOLdFGB2 = -(1328.0d0 * eps_inout_fac * alphapol2 ** 4.0d0)&
+               / (fgb2 ** 5.0d0)
+       dFGBdR1 = ( (R1 / MomoFac1)* ( 2.0d0 - (0.5d0 * ee1) ) )&
+             / ( 2.0d0 * fgb1 )
+       dFGBdR2 = ( (R2 / MomoFac2)* ( 2.0d0 - (0.5d0 * ee2) ) )&
+             / ( 2.0d0 * fgb2 )
+       dFGBdOM2 = (((R1 * R1 * chi1 * om2) / (MomoFac1 * MomoFac1))&
+                * ( 2.0d0 - 0.5d0 * ee1) ) / ( 2.0d0 * fgb1 )
+       dFGBdOM1 = (((R2 * R2 * chi2 * om1) / (MomoFac2 * MomoFac2))&
+                * ( 2.0d0 - 0.5d0 * ee2) ) / ( 2.0d0 * fgb2 )
+       dPOLdR1 = dPOLdFGB1 * dFGBdR1
+!c!       dPOLdR1 = 0.0d0
+       dPOLdR2 = dPOLdFGB2 * dFGBdR2
+!c!       dPOLdR2 = 0.0d0
+       dPOLdOM1 = dPOLdFGB2 * dFGBdOM1
+!c!       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = dPOLdFGB1 * dFGBdOM2
+!c!       dPOLdOM2 = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Elj
+!c! Lennard-Jones 6-12 interaction between heads
+       pom = (pis / Rhead)**6.0d0
+       Elj = 4.0d0 * eps_head * pom * (pom-1.0d0)
+!c! derivative of Elj is Glj
+       dGLJdR = 4.0d0 * eps_head*(((-12.0d0*pis**12.0d0)/(Rhead**13.0d0))&
+             +  ((  6.0d0*pis**6.0d0) /(Rhead**7.0d0)))
+!c!-------------------------------------------------------------------
+!c! Return the results
+!c! These things do the dRdX derivatives, that is
+!c! allow us to change what we see from function that changes with
+!c! distance to function that changes with LOCATION (of the interaction
+!c! site)
+       DO k = 1, 3
+        erhead(k) = Rhead_distance(k)/Rhead
+        erhead_tail(k,1) = ((ctail(k,2)-chead(k,1))/R1)
+        erhead_tail(k,2) = ((chead(k,2)-ctail(k,1))/R2)
+       END DO
+
+       erdxi = scalar( erhead(1), dC_norm(1,i+nres) )
+       erdxj = scalar( erhead(1), dC_norm(1,j+nres) )
+       bat   = scalar( erhead_tail(1,1), dC_norm(1,i+nres) )
+       federmaus = scalar(erhead_tail(1,1),dC_norm(1,j+nres))
+       eagle = scalar( erhead_tail(1,2), dC_norm(1,j+nres) )
+       adler = scalar( erhead_tail(1,2), dC_norm(1,i+nres) )
+       facd1 = d1 * vbld_inv(i+nres)
+       facd2 = d2 * vbld_inv(j+nres)
+       facd3 = dtail(1,itypi,itypj) * vbld_inv(i+nres)
+       facd4 = dtail(2,itypi,itypj) * vbld_inv(j+nres)
+
+!c! Now we add appropriate partial derivatives (one in each dimension)
+       DO k = 1, 3
+        hawk   = (erhead_tail(k,1) + &
+        facd1 * (erhead_tail(k,1) - bat   * dC_norm(k,i+nres)))
+        condor = (erhead_tail(k,2) + &
+        facd2 * (erhead_tail(k,2) - eagle * dC_norm(k,j+nres)))
+
+        pom = erhead(k)+facd1*(erhead(k)-erdxi*dC_norm(k,i+nres))
+        gvdwx(k,i) = gvdwx(k,i) &
+                  - dGCLdR * pom&
+                  - dGGBdR * pom&
+                  - dGCVdR * pom&
+                  - dPOLdR1 * hawk&
+                  - dPOLdR2 * (erhead_tail(k,2)&
+      -facd3 * (erhead_tail(k,2) - adler * dC_norm(k,i+nres)))&
+                  - dGLJdR * pom
+
+        pom = erhead(k)+facd2*(erhead(k)-erdxj*dC_norm(k,j+nres))
+        gvdwx(k,j) = gvdwx(k,j)+ dGCLdR * pom&
+                   + dGGBdR * pom+ dGCVdR * pom&
+                  + dPOLdR1 * (erhead_tail(k,1)&
+      -facd4 * (erhead_tail(k,1) - federmaus * dC_norm(k,j+nres)))&
+                  + dPOLdR2 * condor + dGLJdR * pom
+
+        gvdwc(k,i) = gvdwc(k,i)  &
+                  - dGCLdR * erhead(k)&
+                  - dGGBdR * erhead(k)&
+                  - dGCVdR * erhead(k)&
+                  - dPOLdR1 * erhead_tail(k,1)&
+                  - dPOLdR2 * erhead_tail(k,2)&
+                  - dGLJdR * erhead(k)
+
+        gvdwc(k,j) = gvdwc(k,j)         &
+                  + dGCLdR * erhead(k) &
+                  + dGGBdR * erhead(k) &
+                  + dGCVdR * erhead(k) &
+                  + dPOLdR1 * erhead_tail(k,1) &
+                  + dPOLdR2 * erhead_tail(k,2)&
+                  + dGLJdR * erhead(k)
+
+       END DO
+       RETURN
+      END SUBROUTINE eqq
+!c!-------------------------------------------------------------------
+      SUBROUTINE energy_quad(istate,eheadtail,Ecl,Egb,Epol,Fisocav,Elj,Equad)
+      use comm_momo
+      use calc_data
+
+       double precision eheadtail,Ecl,Egb,Epol,Fisocav,Elj,Equad
+       double precision ener(4)
+       double precision dcosom1(3),dcosom2(3)
+!c! used in Epol derivatives
+       double precision facd3, facd4
+       double precision federmaus, adler
+       integer istate,ii,jj
+       real (kind=8) :: Fgb
+!       print *,"CALLING EQUAD"
+!c! Epol and Gpol analytical parameters
+       alphapol1 = alphapol(itypi,itypj)
+       alphapol2 = alphapol(itypj,itypi)
+!c! Fisocav and Gisocav analytical parameters
+       al1  = alphiso(1,itypi,itypj)
+       al2  = alphiso(2,itypi,itypj)
+       al3  = alphiso(3,itypi,itypj)
+       al4  = alphiso(4,itypi,itypj)
+       csig = (1.0d0 / dsqrt(sigiso1(itypi, itypj)**2.0d0&
+            + sigiso2(itypi,itypj)**2.0d0))
+!c!
+       w1   = wqdip(1,itypi,itypj)
+       w2   = wqdip(2,itypi,itypj)
+       pis  = sig0head(itypi,itypj)
+       eps_head = epshead(itypi,itypj)
+!c! First things first:
+!c! We need to do sc_grad's job with GB and Fcav
+       eom1  = eps2der * eps2rt_om1 &
+             - 2.0D0 * alf1 * eps3der&
+             + sigder * sigsq_om1&
+             + dCAVdOM1
+       eom2  = eps2der * eps2rt_om2 &
+             + 2.0D0 * alf2 * eps3der&
+             + sigder * sigsq_om2&
+             + dCAVdOM2
+       eom12 =  evdwij  * eps1_om12 &
+             + eps2der * eps2rt_om12 &
+             - 2.0D0 * alf12 * eps3der&
+             + sigder *sigsq_om12&
+             + dCAVdOM12
+!c! now some magical transformations to project gradient into
+!c! three cartesian vectors
+       DO k = 1, 3
+        dcosom1(k) = rij * (dc_norm(k,nres+i) - om1 * erij(k))
+        dcosom2(k) = rij * (dc_norm(k,nres+j) - om2 * erij(k))
+        gg(k) = gg(k) + eom1 * dcosom1(k) + eom2 * dcosom2(k)
+!c! this acts on hydrophobic center of interaction
+        gvdwx(k,i)= gvdwx(k,i) - gg(k) &
+                  + (eom12*(dc_norm(k,nres+j)-om12*dc_norm(k,nres+i))&
+                  + eom1*(erij(k)-om1*dc_norm(k,nres+i)))*dsci_inv
+        gvdwx(k,j)= gvdwx(k,j) + gg(k) &
+                  + (eom12*(dc_norm(k,nres+i)-om12*dc_norm(k,nres+j))&
+                  + eom2*(erij(k)-om2*dc_norm(k,nres+j)))*dscj_inv
+!c! this acts on Calpha
+        gvdwc(k,i)=gvdwc(k,i)-gg(k)
+        gvdwc(k,j)=gvdwc(k,j)+gg(k)
+       END DO
+!c! sc_grad is done, now we will compute 
+       eheadtail = 0.0d0
+       eom1 = 0.0d0
+       eom2 = 0.0d0
+       eom12 = 0.0d0
+       DO istate = 1, nstate(itypi,itypj)
+!c*************************************************************
+        IF (istate.ne.1) THEN
+         IF (istate.lt.3) THEN
+          ii = 1
+         ELSE
+          ii = 2
+         END IF
+        jj = istate/ii
+        d1 = dhead(1,ii,itypi,itypj)
+        d2 = dhead(2,jj,itypi,itypj)
+        DO k = 1,3
+         chead(k,1) = c(k, i+nres) + d1 * dc_norm(k, i+nres)
+         chead(k,2) = c(k, j+nres) + d2 * dc_norm(k, j+nres)
+         Rhead_distance(k) = chead(k,2) - chead(k,1)
+        END DO
+!c! pitagoras (root of sum of squares)
+        Rhead = dsqrt( &
+               (Rhead_distance(1)*Rhead_distance(1))  &
+             + (Rhead_distance(2)*Rhead_distance(2))  &
+             + (Rhead_distance(3)*Rhead_distance(3))) 
+        END IF
+        Rhead_sq = Rhead * Rhead
+
+!c! R1 - distance between head of ith side chain and tail of jth sidechain
+!c! R2 - distance between head of jth side chain and tail of ith sidechain
+        R1 = 0.0d0
+        R2 = 0.0d0
+        DO k = 1, 3
+!c! Calculate head-to-tail distances
+         R1=R1+(ctail(k,2)-chead(k,1))**2
+         R2=R2+(chead(k,2)-ctail(k,1))**2
+        END DO
+!c! Pitagoras
+        R1 = dsqrt(R1)
+        R2 = dsqrt(R2)
+        Ecl = (332.0d0 * Qij) / (Rhead * eps_in)
+!c!        Ecl = 0.0d0
+!c!        write (*,*) "Ecl = ", Ecl
+!c! derivative of Ecl is Gcl...
+        dGCLdR = (-332.0d0 * Qij ) / (Rhead_sq * eps_in)
+!c!        dGCLdR = 0.0d0
+        dGCLdOM1 = 0.0d0
+        dGCLdOM2 = 0.0d0
+        dGCLdOM12 = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Generalised Born Solvent Polarization
+        ee0 = dexp(-( Rhead_sq ) / (4.0d0 * a12sq))
+        Fgb = sqrt( ( Rhead_sq ) + a12sq * ee0)
+        Egb = -(332.0d0 * Qij * eps_inout_fac) / Fgb
+!c!        Egb = 0.0d0
+!c!      write (*,*) "a1*a2 = ", a12sq
+!c!      write (*,*) "Rhead = ", Rhead
+!c!      write (*,*) "Rhead_sq = ", Rhead_sq
+!c!      write (*,*) "ee = ", ee
+!c!      write (*,*) "Fgb = ", Fgb
+!c!      write (*,*) "fac = ", eps_inout_fac
+!c!      write (*,*) "Qij = ", Qij
+!c!      write (*,*) "Egb = ", Egb
+!c! Derivative of Egb is Ggb...
+!c! dFGBdR is used by Quad's later...
+        dGGBdFGB = -(-332.0d0 * Qij * eps_inout_fac) / (Fgb * Fgb)
+        dFGBdR = ( Rhead * ( 2.0d0 - (0.5d0 * ee0) ) )&
+               / ( 2.0d0 * Fgb )
+        dGGBdR = dGGBdFGB * dFGBdR
+!c!        dGGBdR = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Fisocav - isotropic cavity creation term
+        pom = Rhead * csig
+        top = al1 * (dsqrt(pom) + al2 * pom - al3)
+        bot = (1.0d0 + al4 * pom**12.0d0)
+        botsq = bot * bot
+        FisoCav = top / bot
+        dtop = al1 * ((1.0d0 / (2.0d0 * dsqrt(pom))) + al2)
+        dbot = 12.0d0 * al4 * pom ** 11.0d0
+        dGCVdR = ((dtop * bot - top * dbot) / botsq) * csig
+!c!        dGCVdR = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Polarization energy
+!c! Epol
+        MomoFac1 = (1.0d0 - chi1 * sqom2)
+        MomoFac2 = (1.0d0 - chi2 * sqom1)
+        RR1  = ( R1 * R1 ) / MomoFac1
+        RR2  = ( R2 * R2 ) / MomoFac2
+        ee1  = exp(-( RR1 / (4.0d0 * a12sq) ))
+        ee2  = exp(-( RR2 / (4.0d0 * a12sq) ))
+        fgb1 = sqrt( RR1 + a12sq * ee1 )
+        fgb2 = sqrt( RR2 + a12sq * ee2 )
+        epol = 332.0d0 * eps_inout_fac * (&
+        (( alphapol1 / fgb1 )**4.0d0)+((alphapol2/fgb2) ** 4.0d0 ))
+!c!        epol = 0.0d0
+!c! derivative of Epol is Gpol...
+        dPOLdFGB1 = -(1328.0d0 * eps_inout_fac * alphapol1 ** 4.0d0)&
+                  / (fgb1 ** 5.0d0)
+        dPOLdFGB2 = -(1328.0d0 * eps_inout_fac * alphapol2 ** 4.0d0)&
+                  / (fgb2 ** 5.0d0)
+        dFGBdR1 = ( (R1 / MomoFac1) &
+                * ( 2.0d0 - (0.5d0 * ee1) ) )&
+                / ( 2.0d0 * fgb1 )
+        dFGBdR2 = ( (R2 / MomoFac2) &
+                * ( 2.0d0 - (0.5d0 * ee2) ) ) &
+                / ( 2.0d0 * fgb2 )
+        dFGBdOM2 = (((R1 * R1 * chi1 * om2) / (MomoFac1 * MomoFac1)) &
+                 * ( 2.0d0 - 0.5d0 * ee1) ) &
+                 / ( 2.0d0 * fgb1 )
+        dFGBdOM1 = (((R2 * R2 * chi2 * om1) / (MomoFac2 * MomoFac2)) &
+                 * ( 2.0d0 - 0.5d0 * ee2) ) &
+                 / ( 2.0d0 * fgb2 )
+        dPOLdR1 = dPOLdFGB1 * dFGBdR1
+!c!        dPOLdR1 = 0.0d0
+        dPOLdR2 = dPOLdFGB2 * dFGBdR2
+!c!        dPOLdR2 = 0.0d0
+        dPOLdOM1 = dPOLdFGB2 * dFGBdOM1
+!c!        dPOLdOM1 = 0.0d0
+        dPOLdOM2 = dPOLdFGB1 * dFGBdOM2
+        pom = (pis / Rhead)**6.0d0
+        Elj = 4.0d0 * eps_head * pom * (pom-1.0d0)
+!c!        Elj = 0.0d0
+!c! derivative of Elj is Glj
+        dGLJdR = 4.0d0 * eps_head &
+            * (((-12.0d0*pis**12.0d0)/(Rhead**13.0d0)) &
+            +  ((  6.0d0*pis**6.0d0) /(Rhead**7.0d0)))
+!c!        dGLJdR = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Equad
+       IF (Wqd.ne.0.0d0) THEN
+        Beta1 = 5.0d0 + 3.0d0 * (sqom12 - 1.0d0) &
+             - 37.5d0  * ( sqom1 + sqom2 ) &
+             + 157.5d0 * ( sqom1 * sqom2 ) &
+             - 45.0d0  * om1*om2*om12
+        fac = -( Wqd / (2.0d0 * Fgb**5.0d0) )
+        Equad = fac * Beta1
+!c!        Equad = 0.0d0
+!c! derivative of Equad...
+        dQUADdR = ((2.5d0 * Wqd * Beta1) / (Fgb**6.0d0)) * dFGBdR
+!c!        dQUADdR = 0.0d0
+        dQUADdOM1 = fac* (-75.0d0*om1 + 315.0d0*om1*sqom2 - 45.0d0*om2*om12)
+!c!        dQUADdOM1 = 0.0d0
+        dQUADdOM2 = fac* (-75.0d0*om2 + 315.0d0*sqom1*om2 - 45.0d0*om1*om12)
+!c!        dQUADdOM2 = 0.0d0
+        dQUADdOM12 = fac * ( 6.0d0*om12 - 45.0d0*om1*om2 )
+       ELSE
+         Beta1 = 0.0d0
+         Equad = 0.0d0
+        END IF
+!c!-------------------------------------------------------------------
+!c! Return the results
+!c! Angular stuff
+        eom1 = dPOLdOM1 + dQUADdOM1
+        eom2 = dPOLdOM2 + dQUADdOM2
+        eom12 = dQUADdOM12
+!c! now some magical transformations to project gradient into
+!c! three cartesian vectors
+        DO k = 1, 3
+         dcosom1(k) = rij * (dc_norm(k,nres+i) - om1 * erij(k))
+         dcosom2(k) = rij * (dc_norm(k,nres+j) - om2 * erij(k))
+         tuna(k) = eom1 * dcosom1(k) + eom2 * dcosom2(k)
+        END DO
+!c! Radial stuff
+        DO k = 1, 3
+         erhead(k) = Rhead_distance(k)/Rhead
+         erhead_tail(k,1) = ((ctail(k,2)-chead(k,1))/R1)
+         erhead_tail(k,2) = ((chead(k,2)-ctail(k,1))/R2)
+        END DO
+        erdxi = scalar( erhead(1), dC_norm(1,i+nres) )
+        erdxj = scalar( erhead(1), dC_norm(1,j+nres) )
+        bat   = scalar( erhead_tail(1,1), dC_norm(1,i+nres) )
+        federmaus = scalar(erhead_tail(1,1),dC_norm(1,j+nres))
+        eagle = scalar( erhead_tail(1,2), dC_norm(1,j+nres) )
+        adler = scalar( erhead_tail(1,2), dC_norm(1,i+nres) )
+        facd1 = d1 * vbld_inv(i+nres)
+        facd2 = d2 * vbld_inv(j+nres)
+        facd3 = dtail(1,itypi,itypj) * vbld_inv(i+nres)
+        facd4 = dtail(2,itypi,itypj) * vbld_inv(j+nres)
+        DO k = 1, 3
+         hawk   = erhead_tail(k,1) + &
+         facd1 * (erhead_tail(k,1) - bat   * dC_norm(k,i+nres))
+         condor = erhead_tail(k,2) + &
+         facd2 * (erhead_tail(k,2) - eagle * dC_norm(k,j+nres))
+
+         pom = erhead(k)+facd1*(erhead(k)-erdxi*dC_norm(k,i+nres))
+!c! this acts on hydrophobic center of interaction
+         gheadtail(k,1,1) = gheadtail(k,1,1) &
+                         - dGCLdR * pom &
+                         - dGGBdR * pom &
+                         - dGCVdR * pom &
+                         - dPOLdR1 * hawk &
+                         - dPOLdR2 * (erhead_tail(k,2) &
+      -facd3 * (erhead_tail(k,2) - adler * dC_norm(k,i+nres)))&
+                         - dGLJdR * pom &
+                         - dQUADdR * pom&
+                         - tuna(k) &
+                 + (eom12*(dc_norm(k,nres+j)-om12*dc_norm(k,nres+i))&
+                 + eom1*(erij(k)-om1*dc_norm(k,nres+i)))*dsci_inv
+
+         pom = erhead(k)+facd2*(erhead(k)-erdxj*dC_norm(k,j+nres))
+!c! this acts on hydrophobic center of interaction
+         gheadtail(k,2,1) = gheadtail(k,2,1)  &
+                         + dGCLdR * pom      &
+                         + dGGBdR * pom      &
+                         + dGCVdR * pom      &
+                         + dPOLdR1 * (erhead_tail(k,1) &
+      -facd4 * (erhead_tail(k,1) - federmaus * dC_norm(k,j+nres))) &
+                         + dPOLdR2 * condor &
+                         + dGLJdR * pom &
+                         + dQUADdR * pom &
+                         + tuna(k) &
+                 + (eom12*(dc_norm(k,nres+i)-om12*dc_norm(k,nres+j)) &
+                 + eom2*(erij(k)-om2*dc_norm(k,nres+j)))*dscj_inv
+
+!c! this acts on Calpha
+         gheadtail(k,3,1) = gheadtail(k,3,1)  &
+                         - dGCLdR * erhead(k)&
+                         - dGGBdR * erhead(k)&
+                         - dGCVdR * erhead(k)&
+                         - dPOLdR1 * erhead_tail(k,1)&
+                         - dPOLdR2 * erhead_tail(k,2)&
+                         - dGLJdR * erhead(k) &
+                         - dQUADdR * erhead(k)&
+                         - tuna(k)
+!c! this acts on Calpha
+         gheadtail(k,4,1) = gheadtail(k,4,1)   &
+                          + dGCLdR * erhead(k) &
+                          + dGGBdR * erhead(k) &
+                          + dGCVdR * erhead(k) &
+                          + dPOLdR1 * erhead_tail(k,1) &
+                          + dPOLdR2 * erhead_tail(k,2) &
+                          + dGLJdR * erhead(k) &
+                          + dQUADdR * erhead(k)&
+                          + tuna(k)
+        END DO
+        ener(istate) = ECL + Egb + Epol + Fisocav + Elj + Equad
+        eheadtail = eheadtail &
+                  + wstate(istate, itypi, itypj) &
+                  * dexp(-betaT * ener(istate))
+!c! foreach cartesian dimension
+        DO k = 1, 3
+!c! foreach of two gvdwx and gvdwc
+         DO l = 1, 4
+          gheadtail(k,l,2) = gheadtail(k,l,2)  &
+                           + wstate( istate, itypi, itypj ) &
+                           * dexp(-betaT * ener(istate)) &
+                           * gheadtail(k,l,1)
+          gheadtail(k,l,1) = 0.0d0
+         END DO
+        END DO
+       END DO
+!c! Here ended the gigantic DO istate = 1, 4, which starts
+!c! at the beggining of the subroutine
+
+       DO k = 1, 3
+        DO l = 1, 4
+         gheadtail(k,l,2) = gheadtail(k,l,2) / eheadtail
+        END DO
+        gvdwx(k,i) = gvdwx(k,i) + gheadtail(k,1,2)
+        gvdwx(k,j) = gvdwx(k,j) + gheadtail(k,2,2)
+        gvdwc(k,i) = gvdwc(k,i) + gheadtail(k,3,2)
+        gvdwc(k,j) = gvdwc(k,j) + gheadtail(k,4,2)
+        DO l = 1, 4
+         gheadtail(k,l,1) = 0.0d0
+         gheadtail(k,l,2) = 0.0d0
+        END DO
+       END DO
+       eheadtail = (-dlog(eheadtail)) / betaT
+       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = 0.0d0
+       dQUADdOM1 = 0.0d0
+       dQUADdOM2 = 0.0d0
+       dQUADdOM12 = 0.0d0
+       RETURN
+      END SUBROUTINE energy_quad
+!!-----------------------------------------------------------
+      SUBROUTINE eqn(Epol)
+      use comm_momo
+      use calc_data
+
+      double precision  facd4, federmaus,epol
+      alphapol1 = alphapol(itypi,itypj)
+!c! R1 - distance between head of ith side chain and tail of jth sidechain
+       R1 = 0.0d0
+       DO k = 1, 3
+!c! Calculate head-to-tail distances
+        R1=R1+(ctail(k,2)-chead(k,1))**2
+       END DO
+!c! Pitagoras
+       R1 = dsqrt(R1)
+
+!c!      R1     = dsqrt((Rtail**2)+((dtail(1,itypi,itypj)
+!c!     &        +dhead(1,1,itypi,itypj))**2))
+!c!      R2     = dsqrt((Rtail**2)+((dtail(2,itypi,itypj)
+!c!     &        +dhead(2,1,itypi,itypj))**2))
+!c--------------------------------------------------------------------
+!c Polarization energy
+!c Epol
+       MomoFac1 = (1.0d0 - chi1 * sqom2)
+       RR1  = R1 * R1 / MomoFac1
+       ee1  = exp(-( RR1 / (4.0d0 * a12sq) ))
+       fgb1 = sqrt( RR1 + a12sq * ee1)
+       epol = 332.0d0 * eps_inout_fac * (( alphapol1 / fgb1 )**4.0d0)
+       dPOLdFGB1 = -(1328.0d0 * eps_inout_fac * alphapol1 ** 4.0d0) &
+               / (fgb1 ** 5.0d0)
+       dFGBdR1 = ( (R1 / MomoFac1) &
+              * ( 2.0d0 - (0.5d0 * ee1) ) ) &
+              / ( 2.0d0 * fgb1 )
+       dFGBdOM2 = (((R1 * R1 * chi1 * om2) / (MomoFac1 * MomoFac1)) &
+                * (2.0d0 - 0.5d0 * ee1) ) &
+                / (2.0d0 * fgb1)
+       dPOLdR1 = dPOLdFGB1 * dFGBdR1
+!c!       dPOLdR1 = 0.0d0
+       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = dPOLdFGB1 * dFGBdOM2
+       DO k = 1, 3
+        erhead_tail(k,1) = ((ctail(k,2)-chead(k,1))/R1)
+       END DO
+       bat = scalar( erhead_tail(1,1), dC_norm(1,i+nres) )
+       federmaus = scalar(erhead_tail(1,1),dC_norm(1,j+nres))
+       facd1 = d1 * vbld_inv(i+nres)
+       facd4 = dtail(2,itypi,itypj) * vbld_inv(j+nres)
+
+       DO k = 1, 3
+        hawk = (erhead_tail(k,1) + &
+        facd1 * (erhead_tail(k,1) - bat * dC_norm(k,i+nres)))
+
+        gvdwx(k,i) = gvdwx(k,i) &
+                   - dPOLdR1 * hawk
+        gvdwx(k,j) = gvdwx(k,j) &
+                   + dPOLdR1 * (erhead_tail(k,1) &
+       -facd4 * (erhead_tail(k,1) - federmaus * dC_norm(k,j+nres)))
+
+        gvdwc(k,i) = gvdwc(k,i)  - dPOLdR1 * erhead_tail(k,1)
+        gvdwc(k,j) = gvdwc(k,j)  + dPOLdR1 * erhead_tail(k,1)
+
+       END DO
+       RETURN
+      END SUBROUTINE eqn
+      SUBROUTINE enq(Epol)
+      use calc_data
+      use comm_momo
+       double precision facd3, adler,epol
+       alphapol2 = alphapol(itypj,itypi)
+!c! R2 - distance between head of jth side chain and tail of ith sidechain
+       R2 = 0.0d0
+       DO k = 1, 3
+!c! Calculate head-to-tail distances
+        R2=R2+(chead(k,2)-ctail(k,1))**2
+       END DO
+!c! Pitagoras
+       R2 = dsqrt(R2)
+
+!c!      R1     = dsqrt((Rtail**2)+((dtail(1,itypi,itypj)
+!c!     &        +dhead(1,1,itypi,itypj))**2))
+!c!      R2     = dsqrt((Rtail**2)+((dtail(2,itypi,itypj)
+!c!     &        +dhead(2,1,itypi,itypj))**2))
+!c------------------------------------------------------------------------
+!c Polarization energy
+       MomoFac2 = (1.0d0 - chi2 * sqom1)
+       RR2  = R2 * R2 / MomoFac2
+       ee2  = exp(-(RR2 / (4.0d0 * a12sq)))
+       fgb2 = sqrt(RR2  + a12sq * ee2)
+       epol = 332.0d0 * eps_inout_fac * ((alphapol2/fgb2) ** 4.0d0 )
+       dPOLdFGB2 = -(1328.0d0 * eps_inout_fac * alphapol2 ** 4.0d0) &
+                / (fgb2 ** 5.0d0)
+       dFGBdR2 = ( (R2 / MomoFac2)  &
+              * ( 2.0d0 - (0.5d0 * ee2) ) ) &
+              / (2.0d0 * fgb2)
+       dFGBdOM1 = (((R2 * R2 * chi2 * om1) / (MomoFac2 * MomoFac2)) &
+                * (2.0d0 - 0.5d0 * ee2) ) &
+                / (2.0d0 * fgb2)
+       dPOLdR2 = dPOLdFGB2 * dFGBdR2
+!c!       dPOLdR2 = 0.0d0
+       dPOLdOM1 = dPOLdFGB2 * dFGBdOM1
+!c!       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Return the results
+!c! (See comments in Eqq)
+       DO k = 1, 3
+        erhead_tail(k,2) = ((chead(k,2)-ctail(k,1))/R2)
+       END DO
+       eagle = scalar( erhead_tail(1,2), dC_norm(1,j+nres) )
+       adler = scalar( erhead_tail(1,2), dC_norm(1,i+nres) )
+       facd2 = d2 * vbld_inv(j+nres)
+       facd3 = dtail(1,itypi,itypj) * vbld_inv(i+nres)
+       DO k = 1, 3
+        condor = (erhead_tail(k,2) &
+       + facd2 * (erhead_tail(k,2) - eagle * dC_norm(k,j+nres)))
+
+        gvdwx(k,i) = gvdwx(k,i) &
+                   - dPOLdR2 * (erhead_tail(k,2) &
+       -facd3 * (erhead_tail(k,2) - adler * dC_norm(k,i+nres)))
+        gvdwx(k,j) = gvdwx(k,j)   &
+                   + dPOLdR2 * condor
+
+        gvdwc(k,i) = gvdwc(k,i) &
+                   - dPOLdR2 * erhead_tail(k,2)
+        gvdwc(k,j) = gvdwc(k,j) &
+                   + dPOLdR2 * erhead_tail(k,2)
+
+       END DO
+      RETURN
+      END SUBROUTINE enq
+      SUBROUTINE eqd(Ecl,Elj,Epol)
+      use calc_data
+      use comm_momo
+       double precision  facd4, federmaus,ecl,elj,epol
+       alphapol1 = alphapol(itypi,itypj)
+       w1        = wqdip(1,itypi,itypj)
+       w2        = wqdip(2,itypi,itypj)
+       pis       = sig0head(itypi,itypj)
+       eps_head   = epshead(itypi,itypj)
+!c!-------------------------------------------------------------------
+!c! R1 - distance between head of ith side chain and tail of jth sidechain
+       R1 = 0.0d0
+       DO k = 1, 3
+!c! Calculate head-to-tail distances
+        R1=R1+(ctail(k,2)-chead(k,1))**2
+       END DO
+!c! Pitagoras
+       R1 = dsqrt(R1)
+
+!c!      R1     = dsqrt((Rtail**2)+((dtail(1,itypi,itypj)
+!c!     &        +dhead(1,1,itypi,itypj))**2))
+!c!      R2     = dsqrt((Rtail**2)+((dtail(2,itypi,itypj)
+!c!     &        +dhead(2,1,itypi,itypj))**2))
+
+!c!-------------------------------------------------------------------
+!c! ecl
+       sparrow  = w1 * Qi * om1
+       hawk     = w2 * Qi * Qi * (1.0d0 - sqom2)
+       Ecl = sparrow / Rhead**2.0d0 &
+           - hawk    / Rhead**4.0d0
+       dGCLdR  = - 2.0d0 * sparrow / Rhead**3.0d0 &
+                 + 4.0d0 * hawk    / Rhead**5.0d0
+!c! dF/dom1
+       dGCLdOM1 = (w1 * Qi) / (Rhead**2.0d0)
+!c! dF/dom2
+       dGCLdOM2 = (2.0d0 * w2 * Qi * Qi * om2) / (Rhead ** 4.0d0)
+!c--------------------------------------------------------------------
+!c Polarization energy
+!c Epol
+       MomoFac1 = (1.0d0 - chi1 * sqom2)
+       RR1  = R1 * R1 / MomoFac1
+       ee1  = exp(-( RR1 / (4.0d0 * a12sq) ))
+       fgb1 = sqrt( RR1 + a12sq * ee1)
+       epol = 332.0d0 * eps_inout_fac * (( alphapol1 / fgb1 )**4.0d0)
+!c!       epol = 0.0d0
+!c!------------------------------------------------------------------
+!c! derivative of Epol is Gpol...
+       dPOLdFGB1 = -(1328.0d0 * eps_inout_fac * alphapol1 ** 4.0d0) &
+               / (fgb1 ** 5.0d0)
+       dFGBdR1 = ( (R1 / MomoFac1)  &
+             * ( 2.0d0 - (0.5d0 * ee1) ) ) &
+             / ( 2.0d0 * fgb1 )
+       dFGBdOM2 = (((R1 * R1 * chi1 * om2) / (MomoFac1 * MomoFac1)) &
+               * (2.0d0 - 0.5d0 * ee1) ) &
+               / (2.0d0 * fgb1)
+       dPOLdR1 = dPOLdFGB1 * dFGBdR1
+!c!       dPOLdR1 = 0.0d0
+       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = dPOLdFGB1 * dFGBdOM2
+!c!       dPOLdOM2 = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Elj
+       pom = (pis / Rhead)**6.0d0
+       Elj = 4.0d0 * eps_head * pom * (pom-1.0d0)
+!c! derivative of Elj is Glj
+       dGLJdR = 4.0d0 * eps_head &
+          * (((-12.0d0*pis**12.0d0)/(Rhead**13.0d0)) &
+          +  ((  6.0d0*pis**6.0d0) /(Rhead**7.0d0)))
+       DO k = 1, 3
+        erhead(k) = Rhead_distance(k)/Rhead
+        erhead_tail(k,1) = ((ctail(k,2)-chead(k,1))/R1)
+       END DO
+
+       erdxi = scalar( erhead(1), dC_norm(1,i+nres) )
+       erdxj = scalar( erhead(1), dC_norm(1,j+nres) )
+       bat = scalar( erhead_tail(1,1), dC_norm(1,i+nres) )
+       federmaus = scalar(erhead_tail(1,1),dC_norm(1,j+nres))
+       facd1 = d1 * vbld_inv(i+nres)
+       facd2 = d2 * vbld_inv(j+nres)
+       facd4 = dtail(2,itypi,itypj) * vbld_inv(j+nres)
+
+       DO k = 1, 3
+        hawk = (erhead_tail(k,1) +  &
+        facd1 * (erhead_tail(k,1) - bat * dC_norm(k,i+nres)))
+
+        pom = erhead(k)+facd1*(erhead(k)-erdxi*dC_norm(k,i+nres))
+        gvdwx(k,i) = gvdwx(k,i)  &
+                   - dGCLdR * pom&
+                   - dPOLdR1 * hawk &
+                   - dGLJdR * pom  
+
+        pom = erhead(k)+facd2*(erhead(k)-erdxj*dC_norm(k,j+nres))
+        gvdwx(k,j) = gvdwx(k,j)    &
+                   + dGCLdR * pom  &
+                   + dPOLdR1 * (erhead_tail(k,1) &
+       -facd4 * (erhead_tail(k,1) - federmaus * dC_norm(k,j+nres))) &
+                   + dGLJdR * pom
+
+
+        gvdwc(k,i) = gvdwc(k,i)          &
+                   - dGCLdR * erhead(k)  &
+                   - dPOLdR1 * erhead_tail(k,1) &
+                   - dGLJdR * erhead(k)
+
+        gvdwc(k,j) = gvdwc(k,j)          &
+                   + dGCLdR * erhead(k)  &
+                   + dPOLdR1 * erhead_tail(k,1) &
+                   + dGLJdR * erhead(k)
+
+       END DO
+       RETURN
+      END SUBROUTINE eqd
+      SUBROUTINE edq(Ecl,Elj,Epol)
+!       IMPLICIT NONE
+       use comm_momo
+      use calc_data
+
+      double precision  facd3, adler,ecl,elj,epol
+       alphapol2 = alphapol(itypj,itypi)
+       w1        = wqdip(1,itypi,itypj)
+       w2        = wqdip(2,itypi,itypj)
+       pis       = sig0head(itypi,itypj)
+       eps_head  = epshead(itypi,itypj)
+!c!-------------------------------------------------------------------
+!c! R2 - distance between head of jth side chain and tail of ith sidechain
+       R2 = 0.0d0
+       DO k = 1, 3
+!c! Calculate head-to-tail distances
+        R2=R2+(chead(k,2)-ctail(k,1))**2
+       END DO
+!c! Pitagoras
+       R2 = dsqrt(R2)
+
+!c!      R1     = dsqrt((Rtail**2)+((dtail(1,itypi,itypj)
+!c!     &        +dhead(1,1,itypi,itypj))**2))
+!c!      R2     = dsqrt((Rtail**2)+((dtail(2,itypi,itypj)
+!c!     &        +dhead(2,1,itypi,itypj))**2))
+
+
+!c!-------------------------------------------------------------------
+!c! ecl
+       sparrow  = w1 * Qi * om1
+       hawk     = w2 * Qi * Qi * (1.0d0 - sqom2)
+       ECL = sparrow / Rhead**2.0d0 &
+           - hawk    / Rhead**4.0d0
+!c!-------------------------------------------------------------------
+!c! derivative of ecl is Gcl
+!c! dF/dr part
+       dGCLdR  = - 2.0d0 * sparrow / Rhead**3.0d0 &
+                 + 4.0d0 * hawk    / Rhead**5.0d0
+!c! dF/dom1
+       dGCLdOM1 = (w1 * Qi) / (Rhead**2.0d0)
+!c! dF/dom2
+       dGCLdOM2 = (2.0d0 * w2 * Qi * Qi * om2) / (Rhead ** 4.0d0)
+!c--------------------------------------------------------------------
+!c Polarization energy
+!c Epol
+       MomoFac2 = (1.0d0 - chi2 * sqom1)
+       RR2  = R2 * R2 / MomoFac2
+       ee2  = exp(-(RR2 / (4.0d0 * a12sq)))
+       fgb2 = sqrt(RR2  + a12sq * ee2)
+       epol = 332.0d0 * eps_inout_fac * ((alphapol2/fgb2) ** 4.0d0 )
+       dPOLdFGB2 = -(1328.0d0 * eps_inout_fac * alphapol2 ** 4.0d0) &
+               / (fgb2 ** 5.0d0)
+       dFGBdR2 = ( (R2 / MomoFac2)  &
+               * ( 2.0d0 - (0.5d0 * ee2) ) ) &
+               / (2.0d0 * fgb2)
+       dFGBdOM1 = (((R2 * R2 * chi2 * om1) / (MomoFac2 * MomoFac2)) &
+                * (2.0d0 - 0.5d0 * ee2) ) &
+                / (2.0d0 * fgb2)
+       dPOLdR2 = dPOLdFGB2 * dFGBdR2
+!c!       dPOLdR2 = 0.0d0
+       dPOLdOM1 = dPOLdFGB2 * dFGBdOM1
+!c!       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = 0.0d0
+!c!-------------------------------------------------------------------
+!c! Elj
+       pom = (pis / Rhead)**6.0d0
+       Elj = 4.0d0 * eps_head * pom * (pom-1.0d0)
+!c! derivative of Elj is Glj
+       dGLJdR = 4.0d0 * eps_head &
+           * (((-12.0d0*pis**12.0d0)/(Rhead**13.0d0)) &
+           +  ((  6.0d0*pis**6.0d0) /(Rhead**7.0d0)))
+!c!-------------------------------------------------------------------
+!c! Return the results
+!c! (see comments in Eqq)
+       DO k = 1, 3
+        erhead(k) = Rhead_distance(k)/Rhead
+        erhead_tail(k,2) = ((chead(k,2)-ctail(k,1))/R2)
+       END DO
+       erdxi = scalar( erhead(1), dC_norm(1,i+nres) )
+       erdxj = scalar( erhead(1), dC_norm(1,j+nres) )
+       eagle = scalar( erhead_tail(1,2), dC_norm(1,j+nres) )
+       adler = scalar( erhead_tail(1,2), dC_norm(1,i+nres) )
+       facd1 = d1 * vbld_inv(i+nres)
+       facd2 = d2 * vbld_inv(j+nres)
+       facd3 = dtail(1,itypi,itypj) * vbld_inv(i+nres)
+       DO k = 1, 3
+        condor = (erhead_tail(k,2) &
+       + facd2 * (erhead_tail(k,2) - eagle * dC_norm(k,j+nres)))
+
+        pom = erhead(k)+facd1*(erhead(k)-erdxi*dC_norm(k,i+nres))
+        gvdwx(k,i) = gvdwx(k,i) &
+                  - dGCLdR * pom &
+                  - dPOLdR2 * (erhead_tail(k,2) &
+       -facd3 * (erhead_tail(k,2) - adler * dC_norm(k,i+nres))) &
+                  - dGLJdR * pom
+
+        pom = erhead(k)+facd2*(erhead(k)-erdxj*dC_norm(k,j+nres))
+        gvdwx(k,j) = gvdwx(k,j) &
+                  + dGCLdR * pom &
+                  + dPOLdR2 * condor &
+                  + dGLJdR * pom
+
+
+        gvdwc(k,i) = gvdwc(k,i) &
+                  - dGCLdR * erhead(k) &
+                  - dPOLdR2 * erhead_tail(k,2) &
+                  - dGLJdR * erhead(k)
+
+        gvdwc(k,j) = gvdwc(k,j) &
+                  + dGCLdR * erhead(k) &
+                  + dPOLdR2 * erhead_tail(k,2) &
+                  + dGLJdR * erhead(k)
+
+       END DO
+       RETURN
+      END SUBROUTINE edq
+      SUBROUTINE edd(ECL)
+!       IMPLICIT NONE
+       use comm_momo
+      use calc_data
+
+       double precision ecl
+!c!       csig = sigiso(itypi,itypj)
+       w1 = wqdip(1,itypi,itypj)
+       w2 = wqdip(2,itypi,itypj)
+!c!-------------------------------------------------------------------
+!c! ECL
+       fac = (om12 - 3.0d0 * om1 * om2)
+       c1 = (w1 / (Rhead**3.0d0)) * fac
+       c2 = (w2 / Rhead ** 6.0d0) &
+          * (4.0d0 + fac * fac -3.0d0 * (sqom1 + sqom2))
+       ECL = c1 - c2
+!c!       write (*,*) "w1 = ", w1
+!c!       write (*,*) "w2 = ", w2
+!c!       write (*,*) "om1 = ", om1
+!c!       write (*,*) "om2 = ", om2
+!c!       write (*,*) "om12 = ", om12
+!c!       write (*,*) "fac = ", fac
+!c!       write (*,*) "c1 = ", c1
+!c!       write (*,*) "c2 = ", c2
+!c!       write (*,*) "Ecl = ", Ecl
+!c!       write (*,*) "c2_1 = ", (w2 / Rhead ** 6.0d0)
+!c!       write (*,*) "c2_2 = ",
+!c!     & (4.0d0 + fac * fac -3.0d0 * (sqom1 + sqom2))
+!c!-------------------------------------------------------------------
+!c! dervative of ECL is GCL...
+!c! dECL/dr
+       c1 = (-3.0d0 * w1 * fac) / (Rhead ** 4.0d0)
+       c2 = (-6.0d0 * w2) / (Rhead ** 7.0d0) &
+          * (4.0d0 + fac * fac - 3.0d0 * (sqom1 + sqom2))
+       dGCLdR = c1 - c2
+!c! dECL/dom1
+       c1 = (-3.0d0 * w1 * om2 ) / (Rhead**3.0d0)
+       c2 = (-6.0d0 * w2) / (Rhead**6.0d0) &
+          * ( om2 * om12 - 3.0d0 * om1 * sqom2 + om1 )
+       dGCLdOM1 = c1 - c2
+!c! dECL/dom2
+       c1 = (-3.0d0 * w1 * om1 ) / (Rhead**3.0d0)
+       c2 = (-6.0d0 * w2) / (Rhead**6.0d0) &
+          * ( om1 * om12 - 3.0d0 * sqom1 * om2 + om2 )
+       dGCLdOM2 = c1 - c2
+!c! dECL/dom12
+       c1 = w1 / (Rhead ** 3.0d0)
+       c2 = ( 2.0d0 * w2 * fac ) / Rhead ** 6.0d0
+       dGCLdOM12 = c1 - c2
+!c!-------------------------------------------------------------------
+!c! Return the results
+!c! (see comments in Eqq)
+       DO k= 1, 3
+        erhead(k) = Rhead_distance(k)/Rhead
+       END DO
+       erdxi = scalar( erhead(1), dC_norm(1,i+nres) )
+       erdxj = scalar( erhead(1), dC_norm(1,j+nres) )
+       facd1 = d1 * vbld_inv(i+nres)
+       facd2 = d2 * vbld_inv(j+nres)
+       DO k = 1, 3
+
+        pom = erhead(k)+facd1*(erhead(k)-erdxi*dC_norm(k,i+nres))
+        gvdwx(k,i) = gvdwx(k,i)    - dGCLdR * pom
+        pom = erhead(k)+facd2*(erhead(k)-erdxj*dC_norm(k,j+nres))
+        gvdwx(k,j) = gvdwx(k,j)    + dGCLdR * pom
+
+        gvdwc(k,i) = gvdwc(k,i)    - dGCLdR * erhead(k)
+        gvdwc(k,j) = gvdwc(k,j)    + dGCLdR * erhead(k)
+       END DO
+       RETURN
+      END SUBROUTINE edd
+      SUBROUTINE elgrad_init(eheadtail,Egb,Ecl,Elj,Equad,Epol)
+!       IMPLICIT NONE
+       use comm_momo
+      use calc_data
+      
+       real(kind=8) :: eheadtail,Egb,Ecl,Elj,Equad,Epol,Rb
+       eps_out=80.0d0
+       itypi = itype(i,1)
+       itypj = itype(j,1)
+!c! 1/(Gas Constant * Thermostate temperature) = BetaT
+!c! ENABLE THIS LINE WHEN USING CHECKGRAD!!!
+!c!       t_bath = 300
+!c!       BetaT = 1.0d0 / (t_bath * Rb)i
+       Rb=0.001986d0
+       BetaT = 1.0d0 / (298.0d0 * Rb)
+!c! Gay-berne var's
+       sig0ij = sigma( itypi,itypj )
+       chi1   = chi( itypi, itypj )
+       chi2   = chi( itypj, itypi )
+       chi12  = chi1 * chi2
+       chip1  = chipp( itypi, itypj )
+       chip2  = chipp( itypj, itypi )
+       chip12 = chip1 * chip2
+!       chi1=0.0
+!       chi2=0.0
+!       chi12=0.0
+!       chip1=0.0
+!       chip2=0.0
+!       chip12=0.0
+!c! not used by momo potential, but needed by sc_angular which is shared
+!c! by all energy_potential subroutines
+       alf1   = 0.0d0
+       alf2   = 0.0d0
+       alf12  = 0.0d0
+!c! location, location, location
+!       xj  = c( 1, nres+j ) - xi
+!       yj  = c( 2, nres+j ) - yi
+!       zj  = c( 3, nres+j ) - zi
+       dxj = dc_norm( 1, nres+j )
+       dyj = dc_norm( 2, nres+j )
+       dzj = dc_norm( 3, nres+j )
+!c! distance from center of chain(?) to polar/charged head
+!c!       write (*,*) "istate = ", 1
+!c!       write (*,*) "ii = ", 1
+!c!       write (*,*) "jj = ", 1
+       d1 = dhead(1, 1, itypi, itypj)
+       d2 = dhead(2, 1, itypi, itypj)
+!c! ai*aj from Fgb
+       a12sq = rborn(itypi,itypj) * rborn(itypj,itypi)
+!c!       a12sq = a12sq * a12sq
+!c! charge of amino acid itypi is...
+       Qi  = icharge(itypi)
+       Qj  = icharge(itypj)
+       Qij = Qi * Qj
+!c! chis1,2,12
+       chis1 = chis(itypi,itypj)
+       chis2 = chis(itypj,itypi)
+       chis12 = chis1 * chis2
+       sig1 = sigmap1(itypi,itypj)
+       sig2 = sigmap2(itypi,itypj)
+!c!       write (*,*) "sig1 = ", sig1
+!c!       write (*,*) "sig2 = ", sig2
+!c! alpha factors from Fcav/Gcav
+       b1cav = alphasur(1,itypi,itypj)
+!       b1cav=0.0
+       b2cav = alphasur(2,itypi,itypj)
+       b3cav = alphasur(3,itypi,itypj)
+       b4cav = alphasur(4,itypi,itypj)
+       wqd = wquad(itypi, itypj)
+!c! used by Fgb
+       eps_in = epsintab(itypi,itypj)
+       eps_inout_fac = ( (1.0d0/eps_in) - (1.0d0/eps_out))
+!c!       write (*,*) "eps_inout_fac = ", eps_inout_fac
+!c!-------------------------------------------------------------------
+!c! tail location and distance calculations
+       Rtail = 0.0d0
+       DO k = 1, 3
+        ctail(k,1)=c(k,i+nres)-dtail(1,itypi,itypj)*dc_norm(k,nres+i)
+        ctail(k,2)=c(k,j+nres)-dtail(2,itypi,itypj)*dc_norm(k,nres+j)
+       END DO
+!c! tail distances will be themselves usefull elswhere
+!c1 (in Gcav, for example)
+       Rtail_distance(1) = ctail( 1, 2 ) - ctail( 1,1 )
+       Rtail_distance(2) = ctail( 2, 2 ) - ctail( 2,1 )
+       Rtail_distance(3) = ctail( 3, 2 ) - ctail( 3,1 )
+       Rtail = dsqrt(  &
+          (Rtail_distance(1)*Rtail_distance(1))  &
+        + (Rtail_distance(2)*Rtail_distance(2))  &
+        + (Rtail_distance(3)*Rtail_distance(3)))
+!c!-------------------------------------------------------------------
+!c! Calculate location and distance between polar heads
+!c! distance between heads
+!c! for each one of our three dimensional space...
+       d1 = dhead(1, 1, itypi, itypj)
+       d2 = dhead(2, 1, itypi, itypj)
+
+       DO k = 1,3
+!c! location of polar head is computed by taking hydrophobic centre
+!c! and moving by a d1 * dc_norm vector
+!c! see unres publications for very informative images
+        chead(k,1) = c(k, i+nres) + d1 * dc_norm(k, i+nres)
+        chead(k,2) = c(k, j+nres) + d2 * dc_norm(k, j+nres)
+!c! distance 
+!c!        Rsc_distance(k) = dabs(c(k, i+nres) - c(k, j+nres))
+!c!        Rsc(k) = Rsc_distance(k) * Rsc_distance(k)
+        Rhead_distance(k) = chead(k,2) - chead(k,1)
+       END DO
+!c! pitagoras (root of sum of squares)
+       Rhead = dsqrt(   &
+          (Rhead_distance(1)*Rhead_distance(1)) &
+        + (Rhead_distance(2)*Rhead_distance(2)) &
+        + (Rhead_distance(3)*Rhead_distance(3)))
+!c!-------------------------------------------------------------------
+!c! zero everything that should be zero'ed
+       Egb = 0.0d0
+       ECL = 0.0d0
+       Elj = 0.0d0
+       Equad = 0.0d0
+       Epol = 0.0d0
+       eheadtail = 0.0d0
+       dGCLdOM1 = 0.0d0
+       dGCLdOM2 = 0.0d0
+       dGCLdOM12 = 0.0d0
+       dPOLdOM1 = 0.0d0
+       dPOLdOM2 = 0.0d0
+       RETURN
+      END SUBROUTINE elgrad_init
       end module energy