SAXS cutoff saxs_cutoff.eq.0
[unres.git] / source / unres / src_MD-M / energy_p_new_barrier.F
index 03dda37..b788da5 100644 (file)
@@ -55,6 +55,7 @@ C FG slaves as WEIGHTS array.
           weights_(17)=wbond
           weights_(18)=scal14
           weights_(21)=wsccor
+          weights_(25)=wsaxs
 C FG Master broadcasts the WEIGHTS_ array
           call MPI_Bcast(weights_(1),n_ene,
      &        MPI_DOUBLE_PRECISION,king,FG_COMM,IERROR)
@@ -81,6 +82,7 @@ C FG slaves receive the WEIGHTS array
           wbond=weights(17)
           scal14=weights(18)
           wsccor=weights(21)
+          wsaxs=weights(25)
         endif
         time_Bcast=time_Bcast+MPI_Wtime()-time00
         time_Bcastw=time_Bcastw+MPI_Wtime()-time00
@@ -266,6 +268,16 @@ cd     &" ecorr",ecorr," ecorr5",ecorr5," ecorr6",ecorr6," eturn6",eturn6
          call multibody_hb(ecorr,ecorr5,ecorr6,n_corr,n_corr1)
 cd         write (iout,*) "multibody_hb ecorr",ecorr
       endif
+c      write (iout,*) "nsaxs",nsaxs," saxs_mode",saxs_mode
+      if (nsaxs.gt.0 .and. saxs_mode.eq.0) then
+        call e_saxs(Esaxs_constr)
+c        write (iout,*) "From Esaxs: Esaxs_constr",Esaxs_constr
+      else if (nsaxs.gt.0 .and. saxs_mode.gt.0) then
+        call e_saxsC(Esaxs_constr)
+c        write (iout,*) "From EsaxsC: Esaxs_constr",Esaxs_constr
+      else
+        Esaxs_constr = 0.0d0
+      endif        
 c      print *,"Processor",myrank," computed Ucorr"
 C 
 C If performing constraint dynamics, call the constraint energy
@@ -334,6 +346,7 @@ C
       energia(22)=eliptran
       energia(23)=Eafmforce
       energia(24)=ehomology_constr
+      energia(25)=Esaxs_constr
 c    Here are the energies showed per procesor if the are more processors 
 c    per molecule then we sum it up in sum_energy subroutine 
 c      print *," Processor",myrank," calls SUM_ENERGY"
@@ -428,6 +441,9 @@ cMS$ATTRIBUTES C ::  proc_proc
       eliptran=energia(22)
       Eafmforce=energia(23)
       ehomology_constr=energia(24)
+      esaxs_constr=energia(25)
+c      write (iout,*) "sum_energy esaxs_constr",esaxs_constr,
+c     &  " wsaxs",wsaxs
 #ifdef SPLITELE
       etot=wsc*evdw+wscp*evdw2+welec*ees+wvdwpp*evdw1
      & +wang*ebe+wtor*etors+wscloc*escloc
@@ -435,7 +451,7 @@ cMS$ATTRIBUTES C ::  proc_proc
      & +wcorr6*ecorr6+wturn4*eello_turn4+wturn3*eello_turn3
      & +wturn6*eturn6+wel_loc*eel_loc+edihcnstr+wtor_d*etors_d
      & +wbond*estr+Uconst+wsccor*esccor+ehomology_constr
-     & +wliptran*eliptran+Eafmforce
+     & +wsaxs*esaxs_constr+wliptran*eliptran+Eafmforce
 #else
       etot=wsc*evdw+wscp*evdw2+welec*(ees+evdw1)
      & +wang*ebe+wtor*etors+wscloc*escloc
@@ -443,7 +459,7 @@ cMS$ATTRIBUTES C ::  proc_proc
      & +wcorr6*ecorr6+wturn4*eello_turn4+wturn3*eello_turn3
      & +wturn6*eturn6+wel_loc*eel_loc+edihcnstr+wtor_d*etors_d
      & +wbond*estr+Uconst+wsccor*esccor+ehomology_constr
-     & +wliptran*eliptran
+     & +wsaxs*esaxs_constr+wliptran*eliptran
      & +Eafmforce
 #endif
       energia(0)=etot
@@ -502,12 +518,20 @@ cMS$ATTRIBUTES C ::  proc_proc
 #endif
 #ifdef DEBUG
       write (iout,*) "sum_gradient gvdwc, gvdwx"
-      do i=1,nres
-        write (iout,'(i3,3f10.5,5x,3f10.5,5x,f10.5)') 
+      do i=0,nres
+        write (iout,'(i3,3e15.5,5x,3e15.5)') 
      &   i,(gvdwx(j,i),j=1,3),(gvdwc(j,i),j=1,3)
       enddo
       call flush(iout)
 #endif
+#ifdef DEBUG
+      write (iout,*) "sum_gradient gsaxsc, gsaxsx"
+      do i=0,nres
+        write (iout,'(i3,3e15.5,5x,3e15.5)') 
+     &   i,(gsaxsc(j,i),j=1,3),(gsaxsx(j,i),j=1,3)
+      enddo
+      call flush(iout)
+#endif
 #ifdef MPI
 C FG slaves call the following matching MPI_Bcast in ERGASTULUM
         if (nfgtasks.gt.1 .and. fg_rank.eq.0) 
@@ -547,7 +571,8 @@ c      enddo
      &                wcorr5*gradcorr5_long(j,i)+
      &                wcorr6*gradcorr6_long(j,i)+
      &                wturn6*gcorr6_turn_long(j,i)+
-     &                wstrain*ghpbc(j,i)
+     &                wstrain*ghpbc(j,i)+
+     &                wsaxs*gsaxsc(j,i)
      &                +wliptran*gliptranc(j,i)
      &                +gradafm(j,i)
 
@@ -565,7 +590,8 @@ c      enddo
      &                wcorr5*gradcorr5_long(j,i)+
      &                wcorr6*gradcorr6_long(j,i)+
      &                wturn6*gcorr6_turn_long(j,i)+
-     &                wstrain*ghpbc(j,i)
+     &                wstrain*ghpbc(j,i)+
+     &                wsaxs*gsaxsc(j,i)
      &                +wliptran*gliptranc(j,i)
      &                +gradafm(j,i)
 
@@ -625,7 +651,8 @@ c      enddo
       do j=1,3
         gradbufc(j,nres-1)=gradbufc_sum(j,nres)
       enddo
-      do i=nres-2,-1,-1
+      do i=nres-2,0,-1
+c      do i=nres-2,nnt,-1
         do j=1,3
           gradbufc(j,i)=gradbufc(j,i+1)+gradbufc_sum(j,i+1)
         enddo
@@ -633,7 +660,7 @@ c      enddo
 #ifdef DEBUG
       write (iout,*) "gradbufc after summing"
       do i=1,nres
-        write (iout,'(i3,3f10.5)') i,(gradbufc(j,i),j=1,3)
+        write (iout,'(i3,3e15.5)') i,(gradbufc(j,i),j=1,3)
       enddo
       call flush(iout)
 #endif
@@ -641,8 +668,8 @@ c      enddo
 #endif
 #ifdef DEBUG
       write (iout,*) "gradbufc"
-      do i=1,nres
-        write (iout,'(i3,3f10.5)') i,(gradbufc(j,i),j=1,3)
+      do i=0,nres
+        write (iout,'(i3,3e15.5)') i,(gradbufc(j,i),j=1,3)
       enddo
       call flush(iout)
 #endif
@@ -655,7 +682,8 @@ c      enddo
       do j=1,3
         gradbufc(j,nres-1)=gradbufc_sum(j,nres)
       enddo
-      do i=nres-2,-1,-1
+      do i=nres-2,0,-1
+c      do i=nres-2,nnt,-1
         do j=1,3
           gradbufc(j,i)=gradbufc(j,i+1)+gradbufc_sum(j,i+1)
         enddo
@@ -672,8 +700,8 @@ c        enddo
 c      enddo
 #ifdef DEBUG
       write (iout,*) "gradbufc after summing"
-      do i=1,nres
-        write (iout,'(i3,3f10.5)') i,(gradbufc(j,i),j=1,3)
+      do i=0,nres
+        write (iout,'(i3,3e15.5)') i,(gradbufc(j,i),j=1,3)
       enddo
       call flush(iout)
 #endif
@@ -731,8 +759,9 @@ c      enddo
 #endif
           gradx(j,i,icg)=wsc*gvdwx(j,i)+wscp*gradx_scp(j,i)+
      &                  wbond*gradbx(j,i)+
-     &                  wstrain*ghpbx(j,i)+wcorr*gradxorr(j,i)+
-     &                  wsccor*gsccorx(j,i)
+     &                  wstrain*ghpbx(j,i)+wcorr*gradxorr(j,i)
+     &                 +wsaxs*gsaxsx(j,i)
+     &                 +wsccor*gsccorx(j,i)
      &                 +wscloc*gsclocx(j,i)
      &                 +wliptran*gliptranx(j,i)
         enddo
@@ -929,7 +958,7 @@ c
 #ifdef DEBUG
       write (iout,*) "gradc gradx gloc"
       do i=1,nres
-        write (iout,'(i5,3f10.5,5x,3f10.5,5x,f10.5)') 
+        write (iout,'(i5,3e15.5,5x,3e15.5,5x,e15.5)') 
      &   i,(gradc(j,i,icg),j=1,3),(gradx(j,i,icg),j=1,3),gloc(i,icg)
       enddo 
 #endif
@@ -1032,6 +1061,7 @@ C------------------------------------------------------------------------
       Uconst=energia(20)
       esccor=energia(21)
       ehomology_constr=energia(24)
+      esaxs_constr=energia(25)
       eliptran=energia(22)
       Eafmforce=energia(23) 
 #ifdef SPLITELE
@@ -1041,7 +1071,7 @@ C------------------------------------------------------------------------
      &  ecorr,wcorr,
      &  ecorr5,wcorr5,ecorr6,wcorr6,eel_loc,wel_loc,eello_turn3,wturn3,
      &  eello_turn4,wturn4,eello_turn6,wturn6,esccor,wsccor,
-     &  edihcnstr,ehomology_constr, ebr*nss,
+     &  edihcnstr,ehomology_constr,esaxs_constr*wsaxs, ebr*nss,
      &  Uconst,eliptran,wliptran,Eafmforce,etot
    10 format (/'Virtual-chain energies:'//
      & 'EVDW=  ',1pE16.6,' WEIGHT=',1pD16.6,' (SC-SC)'/
@@ -1065,6 +1095,7 @@ C------------------------------------------------------------------------
      & 'ESCCOR=',1pE16.6,' WEIGHT=',1pD16.6,' (backbone-rotamer corr)'/
      & 'EDIHC= ',1pE16.6,' (dihedral angle constraints)'/
      & 'H_CONS=',1pE16.6,' (Homology model constraints energy)'/
+     & 'E_SAXS=',1pE16.6,' (SAXS restraints)'/
      & 'ESS=   ',1pE16.6,' (disulfide-bridge intrinsic energy)'/
      & 'UCONST= ',1pE16.6,' (Constraint energy)'/ 
      & 'ELT=',1pE16.6, ' WEIGHT=',1pD16.6,' (Lipid transfer energy)'/
@@ -1078,7 +1109,7 @@ C------------------------------------------------------------------------
      &  ecorr,wcorr,
      &  ecorr5,wcorr5,ecorr6,wcorr6,eel_loc,wel_loc,eello_turn3,wturn3,
      &  eello_turn4,wturn4,eello_turn6,wturn6,esccor,wsccro,edihcnstr,
-     &  ehomology_constr,ebr*nss,Uconst,
+     &  ehomology_constr,esaxs_constr*wsaxs,ebr*nss,Uconst,
      &  eliptran,wliptran,Eafmforc,
      &  etot
    10 format (/'Virtual-chain energies:'//
@@ -1102,6 +1133,7 @@ C------------------------------------------------------------------------
      & 'ESCCOR=',1pE16.6,' WEIGHT=',1pD16.6,' (backbone-rotamer corr)'/
      & 'EDIHC= ',1pE16.6,' (dihedral angle constraints)'/
      & 'H_CONS=',1pE16.6,' (Homology model constraints energy)'/
+     & 'E_SAXS=',1pE16.6,' (SAXS restraints)'/
      & 'ESS=   ',1pE16.6,' (disulfide-bridge intrinsic energy)'/
      & 'UCONST=',1pE16.6,' (Constraint energy)'/ 
      & 'ELT=',1pE16.6, ' WEIGHT=',1pD16.6,' (Lipid transfer energy)'/
@@ -4393,6 +4425,7 @@ C Derivatives in gamma(i+1)
         gel_loc_turn3(i+1)=gel_loc_turn3(i+1)
      &    +0.5d0*(pizda(1,1)+pizda(2,2))
 C Cartesian derivatives
+!DIR$ UNROLL(0)
         do l=1,3
 c            ghalf1=0.5d0*agg(l,1)
 c            ghalf2=0.5d0*agg(l,2)
@@ -7115,7 +7148,7 @@ c       grad_dih3=sum_sgdih/sum_gdih
 c      write(iout,*)i,k,gdih,sgdih,beta(i+1,i+2,i+3,i+4),grad_dih3
 ccc      write(iout,747) "GRAD_KAT_1", i, nphi, icg, grad_dih3,
 ccc     & gloc(nphi+i-3,icg)
-        gloc(i,icg)=gloc(i,icg)+grad_dih3
+        gloc(i-3,icg)=gloc(i-3,icg)+grad_dih3
 c        if (i.eq.25) then
 c        write(iout,*) "i",i,"icg",icg,"gloc(",i,icg,")",gloc(i,icg)
 c        endif
@@ -11016,3 +11049,417 @@ C      print *,'AFM',Eafmforce,totTafm*velAFMconst,dist
       return
       end
 
+c----------------------------------------------------------------------------
+      double precision function sscale2(r,r_cut,r0,rlamb)
+      implicit none
+      double precision r,gamm,r_cut,r0,rlamb,rr
+      rr = dabs(r-r0)
+c      write (2,*) "r",r," r_cut",r_cut," r0",r0," rlamb",rlamb
+c      write (2,*) "rr",rr
+      if(rr.lt.r_cut-rlamb) then
+        sscale2=1.0d0
+      else if(rr.le.r_cut.and.rr.ge.r_cut-rlamb) then
+        gamm=(rr-(r_cut-rlamb))/rlamb
+        sscale2=1.0d0+gamm*gamm*(2*gamm-3.0d0)
+      else
+        sscale2=0d0
+      endif
+      return
+      end
+C-----------------------------------------------------------------------
+      double precision function sscalgrad2(r,r_cut,r0,rlamb)
+      implicit none
+      double precision r,gamm,r_cut,r0,rlamb,rr
+      rr = dabs(r-r0)
+      if(rr.lt.r_cut-rlamb) then
+        sscalgrad2=0.0d0
+      else if(rr.le.r_cut.and.rr.ge.r_cut-rlamb) then
+        gamm=(rr-(r_cut-rlamb))/rlamb
+        if (r.ge.r0) then
+          sscalgrad2=gamm*(6*gamm-6.0d0)/rlamb
+        else
+          sscalgrad2=-gamm*(6*gamm-6.0d0)/rlamb
+        endif
+      else
+        sscalgrad2=0.0d0
+      endif
+      return
+      end
+c----------------------------------------------------------------------------
+      subroutine e_saxs(Esaxs_constr)
+      implicit none
+      include 'DIMENSIONS'
+#ifdef MPI
+      include "mpif.h"
+      include "COMMON.SETUP"
+      integer IERR
+#endif
+      include 'COMMON.SBRIDGE'
+      include 'COMMON.CHAIN'
+      include 'COMMON.GEO'
+      include 'COMMON.DERIV'
+      include 'COMMON.LOCAL'
+      include 'COMMON.INTERACT'
+      include 'COMMON.VAR'
+      include 'COMMON.IOUNITS'
+      include 'COMMON.MD'
+      include 'COMMON.CONTROL'
+      include 'COMMON.NAMES'
+      include 'COMMON.TIME1'
+      include 'COMMON.FFIELD'
+c
+      double precision Esaxs_constr
+      integer i,iint,j,k,l
+      double precision PgradC(maxSAXS,3,maxres),
+     &  PgradX(maxSAXS,3,maxres),Pcalc(maxSAXS)
+#ifdef MPI
+      double precision PgradC_(maxSAXS,3,maxres),
+     &  PgradX_(maxSAXS,3,maxres),Pcalc_(maxSAXS)
+#endif
+      double precision dk,dijCACA,dijCASC,dijSCCA,dijSCSC,
+     & sigma2CACA,sigma2CASC,sigma2SCCA,sigma2SCSC,expCACA,expCASC,
+     & expSCCA,expSCSC,CASCgrad,SCCAgrad,SCSCgrad,aux,auxC,auxC1,
+     & auxX,auxX1,CACAgrad,Cnorm
+      double precision sss2,ssgrad2,rrr,sscalgrad2,sscale2
+      double precision dist
+      external dist
+c  SAXS restraint penalty function
+#ifdef DEBUG
+      write(iout,*) "------- SAXS penalty function start -------"
+      write (iout,*) "nsaxs",nsaxs
+      write (iout,*) "Esaxs: iatsc_s",iatsc_s," iatsc_e",iatsc_e
+      write (iout,*) "Psaxs"
+      do i=1,nsaxs
+        write (iout,'(i5,e15.5)') i, Psaxs(i)
+      enddo
+#endif
+      Esaxs_constr = 0.0d0
+      do k=1,nsaxs
+        Pcalc(k)=0.0d0
+        do j=1,nres
+          do l=1,3
+            PgradC(k,l,j)=0.0d0
+            PgradX(k,l,j)=0.0d0
+          enddo
+        enddo
+      enddo
+      do i=iatsc_s,iatsc_e
+       if (itype(i).eq.ntyp1) cycle
+       do iint=1,nint_gr(i)
+         do j=istart(i,iint),iend(i,iint)
+           if (itype(j).eq.ntyp1) cycle
+#ifdef ALLSAXS
+           dijCACA=dist(i,j)
+           dijCASC=dist(i,j+nres)
+           dijSCCA=dist(i+nres,j)
+           dijSCSC=dist(i+nres,j+nres)
+           sigma2CACA=2.0d0/(pstok**2)
+           sigma2CASC=4.0d0/(pstok**2+restok(itype(j))**2)
+           sigma2SCCA=4.0d0/(pstok**2+restok(itype(i))**2)
+           sigma2SCSC=4.0d0/(restok(itype(j))**2+restok(itype(i))**2)
+           do k=1,nsaxs
+             dk = distsaxs(k)
+             expCACA = dexp(-0.5d0*sigma2CACA*(dijCACA-dk)**2)
+             if (itype(j).ne.10) then
+             expCASC = dexp(-0.5d0*sigma2CASC*(dijCASC-dk)**2)
+             else
+             endif
+             expCASC = 0.0d0
+             if (itype(i).ne.10) then
+             expSCCA = dexp(-0.5d0*sigma2SCCA*(dijSCCA-dk)**2)
+             else 
+             expSCCA = 0.0d0
+             endif
+             if (itype(i).ne.10 .and. itype(j).ne.10) then
+             expSCSC = dexp(-0.5d0*sigma2SCSC*(dijSCSC-dk)**2)
+             else
+             expSCSC = 0.0d0
+             endif
+             Pcalc(k) = Pcalc(k)+expCACA+expCASC+expSCCA+expSCSC
+#ifdef DEBUG
+             write(iout,*) "i j k Pcalc",i,j,Pcalc(k)
+#endif
+             CACAgrad = sigma2CACA*(dijCACA-dk)*expCACA
+             CASCgrad = sigma2CASC*(dijCASC-dk)*expCASC
+             SCCAgrad = sigma2SCCA*(dijSCCA-dk)*expSCCA
+             SCSCgrad = sigma2SCSC*(dijSCSC-dk)*expSCSC
+             do l=1,3
+c CA CA 
+               aux = CACAgrad*(C(l,j)-C(l,i))/dijCACA
+               PgradC(k,l,i) = PgradC(k,l,i)-aux
+               PgradC(k,l,j) = PgradC(k,l,j)+aux
+c CA SC
+               if (itype(j).ne.10) then
+               aux = CASCgrad*(C(l,j+nres)-C(l,i))/dijCASC
+               PgradC(k,l,i) = PgradC(k,l,i)-aux
+               PgradC(k,l,j) = PgradC(k,l,j)+aux
+               PgradX(k,l,j) = PgradX(k,l,j)+aux
+               endif
+c SC CA
+               if (itype(i).ne.10) then
+               aux = SCCAgrad*(C(l,j)-C(l,i+nres))/dijSCCA
+               PgradX(k,l,i) = PgradX(k,l,i)-aux
+               PgradC(k,l,i) = PgradC(k,l,i)-aux
+               PgradC(k,l,j) = PgradC(k,l,j)+aux
+               endif
+c SC SC
+               if (itype(i).ne.10 .and. itype(j).ne.10) then
+               aux = SCSCgrad*(C(l,j+nres)-C(l,i+nres))/dijSCSC
+               PgradC(k,l,i) = PgradC(k,l,i)-aux
+               PgradC(k,l,j) = PgradC(k,l,j)+aux
+               PgradX(k,l,i) = PgradX(k,l,i)-aux
+               PgradX(k,l,j) = PgradX(k,l,j)+aux
+               endif
+             enddo ! l
+           enddo ! k
+#else
+           dijCACA=dist(i,j)
+           sigma2CACA=scal_rad**2*0.25d0/
+     &        (restok(itype(j))**2+restok(itype(i))**2)
+
+           IF (saxs_cutoff.eq.0) THEN
+           do k=1,nsaxs
+             dk = distsaxs(k)
+             expCACA = dexp(-0.5d0*sigma2CACA*(dijCACA-dk)**2)
+             Pcalc(k) = Pcalc(k)+expCACA
+             CACAgrad = sigma2CACA*(dijCACA-dk)*expCACA
+             do l=1,3
+               aux = CACAgrad*(C(l,j)-C(l,i))/dijCACA
+               PgradC(k,l,i) = PgradC(k,l,i)-aux
+               PgradC(k,l,j) = PgradC(k,l,j)+aux
+             enddo ! l
+           enddo ! k
+           ELSE
+           rrr = saxs_cutoff*2.0d0/dsqrt(sigma2CACA)
+           do k=1,nsaxs
+             dk = distsaxs(k)
+c             write (2,*) "ijk",i,j,k
+             sss2 = sscale2(dijCACA,rrr,dk,0.3d0)
+             if (sss2.eq.0.0d0) cycle
+             ssgrad2 = sscalgrad2(dijCACA,rrr,dk,0.3d0)
+             if (energy_dec) write(iout,'(a4,3i5,5f10.4)') 
+     &          'saxs',i,j,k,dijCACA,rrr,dk,sss2,ssgrad2
+             expCACA = dexp(-0.5d0*sigma2CACA*(dijCACA-dk)**2)*sss2
+             Pcalc(k) = Pcalc(k)+expCACA
+#ifdef DEBUG
+             write(iout,*) "i j k Pcalc",i,j,Pcalc(k)
+#endif
+             CACAgrad = -sigma2CACA*(dijCACA-dk)*expCACA+
+     &             ssgrad2*expCACA/sss2
+             do l=1,3
+c CA CA 
+               aux = CACAgrad*(C(l,j)-C(l,i))/dijCACA
+               PgradC(k,l,i) = PgradC(k,l,i)+aux
+               PgradC(k,l,j) = PgradC(k,l,j)-aux
+             enddo ! l
+           enddo ! k
+           ENDIF
+#endif
+         enddo ! j
+       enddo ! iint
+      enddo ! i
+#ifdef MPI
+      if (nfgtasks.gt.1) then 
+        call MPI_Reduce(Pcalc(1),Pcalc_(1),nsaxs,MPI_DOUBLE_PRECISION,
+     &    MPI_SUM,king,FG_COMM,IERR)
+        if (fg_rank.eq.king) then
+          do k=1,nsaxs
+            Pcalc(k) = Pcalc_(k)
+          enddo
+        endif
+        call MPI_Reduce(PgradC(k,1,1),PgradC_(k,1,1),3*maxsaxs*nres,
+     &    MPI_DOUBLE_PRECISION,MPI_SUM,king,FG_COMM,IERR)
+        if (fg_rank.eq.king) then
+          do i=1,nres
+            do l=1,3
+              do k=1,nsaxs
+                PgradC(k,l,i) = PgradC_(k,l,i)
+              enddo
+            enddo
+          enddo
+        endif
+#ifdef ALLSAXS
+        call MPI_Reduce(PgradX(k,1,1),PgradX_(k,1,1),3*maxsaxs*nres,
+     &    MPI_DOUBLE_PRECISION,MPI_SUM,king,FG_COMM,IERR)
+        if (fg_rank.eq.king) then
+          do i=1,nres
+            do l=1,3
+              do k=1,nsaxs
+                PgradX(k,l,i) = PgradX_(k,l,i)
+              enddo
+            enddo
+          enddo
+        endif
+#endif
+      endif
+#endif
+#ifdef MPI
+      if (fg_rank.eq.king) then
+#endif
+      Cnorm = 0.0d0
+      do k=1,nsaxs
+        Cnorm = Cnorm + Pcalc(k)
+      enddo
+      Esaxs_constr = dlog(Cnorm)
+      do k=1,nsaxs
+        if (Pcalc(k).gt.0.0d0) 
+     &  Esaxs_constr = Esaxs_constr - Psaxs(k)*dlog(Pcalc(k)) 
+#ifdef DEBUG
+        write (iout,*) "k",k," Esaxs_constr",Esaxs_constr
+#endif
+      enddo
+#ifdef DEBUG
+      write (iout,*) "Cnorm",Cnorm," Esaxs_constr",Esaxs_constr
+#endif
+      do i=nnt,nct
+        do l=1,3
+          auxC=0.0d0
+          auxC1=0.0d0
+          auxX=0.0d0
+          auxX1=0.d0 
+          do k=1,nsaxs
+            if (Pcalc(k).gt.0) 
+     &      auxC  = auxC +Psaxs(k)*PgradC(k,l,i)/Pcalc(k)
+            auxC1 = auxC1+PgradC(k,l,i)
+#ifdef ALLSAXS
+            auxX  = auxX +Psaxs(k)*PgradX(k,l,i)/Pcalc(k)
+            auxX1 = auxX1+PgradX(k,l,i)
+#endif
+          enddo
+          gsaxsC(l,i) = auxC - auxC1/Cnorm
+#ifdef ALLSAXS
+          gsaxsX(l,i) = auxX - auxX1/Cnorm
+#endif
+c          write (iout,*) "l i",l,i," gradC",wsaxs*(auxC - auxC1/Cnorm),
+c     *     " gradX",wsaxs*(auxX - auxX1/Cnorm)
+        enddo
+      enddo
+#ifdef MPI
+      endif
+#endif
+      return
+      end
+c----------------------------------------------------------------------------
+      subroutine e_saxsC(Esaxs_constr)
+      implicit none
+      include 'DIMENSIONS'
+#ifdef MPI
+      include "mpif.h"
+      include "COMMON.SETUP"
+      integer IERR
+#endif
+      include 'COMMON.SBRIDGE'
+      include 'COMMON.CHAIN'
+      include 'COMMON.GEO'
+      include 'COMMON.DERIV'
+      include 'COMMON.LOCAL'
+      include 'COMMON.INTERACT'
+      include 'COMMON.VAR'
+      include 'COMMON.IOUNITS'
+      include 'COMMON.MD'
+      include 'COMMON.CONTROL'
+      include 'COMMON.NAMES'
+      include 'COMMON.TIME1'
+      include 'COMMON.FFIELD'
+c
+      double precision Esaxs_constr
+      integer i,iint,j,k,l
+      double precision PgradC(3,maxres),PgradX(3,maxres),Pcalc,logPtot
+#ifdef MPI
+      double precision gsaxsc_(3,maxres),gsaxsx_(3,maxres),logPtot_
+#endif
+      double precision dk,dijCASPH,dijSCSPH,
+     & sigma2CA,sigma2SC,expCASPH,expSCSPH,
+     & CASPHgrad,SCSPHgrad,aux,auxC,auxC1,
+     & auxX,auxX1,Cnorm
+c  SAXS restraint penalty function
+#ifdef DEBUG
+      write(iout,*) "------- SAXS penalty function start -------"
+      write (iout,*) "nsaxs",nsaxs
+
+      do i=nnt,nct
+        print *,MyRank,"C",i,(C(j,i),j=1,3)
+      enddo
+      do i=nnt,nct
+        print *,MyRank,"CSaxs",i,(Csaxs(j,i),j=1,3)
+      enddo
+#endif
+      Esaxs_constr = 0.0d0
+      logPtot=0.0d0
+      do j=isaxs_start,isaxs_end
+        Pcalc=0.0d0
+        do i=1,nres
+          do l=1,3
+            PgradC(l,i)=0.0d0
+            PgradX(l,i)=0.0d0
+          enddo
+        enddo
+        do i=nnt,nct
+          if (itype(i).eq.ntyp1) cycle
+          dijCASPH=0.0d0
+          dijSCSPH=0.0d0
+          do l=1,3
+            dijCASPH=dijCASPH+(C(l,i)-Csaxs(l,j))**2
+          enddo
+          if (itype(i).ne.10) then
+          do l=1,3
+            dijSCSPH=dijSCSPH+(C(l,i+nres)-Csaxs(l,j))**2
+          enddo
+          endif
+          sigma2CA=2.0d0/pstok**2
+          sigma2SC=4.0d0/restok(itype(i))**2
+          expCASPH = dexp(-0.5d0*sigma2CA*dijCASPH)
+          expSCSPH = dexp(-0.5d0*sigma2SC*dijSCSPH)
+          Pcalc = Pcalc+expCASPH+expSCSPH
+#ifdef DEBUG
+          write(*,*) "processor i j Pcalc",
+     &       MyRank,i,j,dijCASPH,dijSCSPH, Pcalc
+#endif
+          CASPHgrad = sigma2CA*expCASPH
+          SCSPHgrad = sigma2SC*expSCSPH
+          do l=1,3
+            aux = (C(l,i+nres)-Csaxs(l,j))*SCSPHgrad
+            PgradX(l,i) = PgradX(l,i) + aux
+            PgradC(l,i) = PgradC(l,i)+(C(l,i)-Csaxs(l,j))*CASPHgrad+aux
+          enddo ! l
+        enddo ! i
+        do i=nnt,nct
+          do l=1,3
+            gsaxsc(l,i)=gsaxsc(l,i)+PgradC(l,i)/Pcalc
+            gsaxsx(l,i)=gsaxsx(l,i)+PgradX(l,i)/Pcalc
+          enddo
+        enddo
+        logPtot = logPtot - dlog(Pcalc) 
+c        print *,"me",me,MyRank," j",j," logPcalc",-dlog(Pcalc),
+c     &    " logPtot",logPtot
+      enddo ! j
+#ifdef MPI
+      if (nfgtasks.gt.1) then 
+c        write (iout,*) "logPtot before reduction",logPtot
+        call MPI_Reduce(logPtot,logPtot_,1,MPI_DOUBLE_PRECISION,
+     &    MPI_SUM,king,FG_COMM,IERR)
+        logPtot = logPtot_
+c        write (iout,*) "logPtot after reduction",logPtot
+        call MPI_Reduce(gsaxsC(1,1),gsaxsC_(1,1),3*nres,
+     &    MPI_DOUBLE_PRECISION,MPI_SUM,king,FG_COMM,IERR)
+        if (fg_rank.eq.king) then
+          do i=1,nres
+            do l=1,3
+              gsaxsC(l,i) = gsaxsC_(l,i)
+            enddo
+          enddo
+        endif
+        call MPI_Reduce(gsaxsX(1,1),gsaxsX_(1,1),3*nres,
+     &    MPI_DOUBLE_PRECISION,MPI_SUM,king,FG_COMM,IERR)
+        if (fg_rank.eq.king) then
+          do i=1,nres
+            do l=1,3
+              gsaxsX(l,i) = gsaxsX_(l,i)
+            enddo
+          enddo
+        endif
+      endif
+#endif
+      Esaxs_constr = logPtot
+      return
+      end