subroutine int_to_cart
c--------------------------------------------------------------         
c  This subroutine converts the energy derivatives from internal 
c  coordinates to cartesian coordinates
c-------------------------------------------------------------
      implicit real*8 (a-h,o-z)
      include 'DIMENSIONS'
      include 'COMMON.VAR'
      include 'COMMON.CHAIN'
      include 'COMMON.DERIV'
      include 'COMMON.GEO'
      include 'COMMON.LOCAL'
      include 'COMMON.INTERACT'
      include 'COMMON.MD'
      include 'COMMON.IOUNITS'
      
c   calculating dE/ddc1      
       if (nres.lt.3) return
       do j=1,3
         gcart(j,1)=gcart(j,1)+gloc(1,icg)*dphi(j,1,4)
     &     +gloc(nres-2,icg)*dtheta(j,1,3)	 
         if(itype(2).ne.10) then
          gcart(j,1)=gcart(j,1)+gloc(ialph(2,1),icg)*dalpha(j,1,2)+
     &    gloc(ialph(2,1)+nside,icg)*domega(j,1,2)	        
        endif
       enddo
c     Calculating the remainder of dE/ddc2
       do j=1,3
         gcart(j,2)=gcart(j,2)+gloc(1,icg)*dphi(j,2,4)+
     &	 gloc(nres-2,icg)*dtheta(j,2,3)+gloc(nres-1,icg)*dtheta(j,1,4)
        if(itype(2).ne.10) then
          gcart(j,2)=gcart(j,2)+gloc(ialph(2,1),icg)*dalpha(j,2,2)+
     &    gloc(ialph(2,1)+nside,icg)*domega(j,2,2)
        endif
       	if(itype(3).ne.10) then
      	  gcart(j,2)=gcart(j,2)+gloc(ialph(3,1),icg)*dalpha(j,1,3)+
     &    gloc(ialph(3,1)+nside,icg)*domega(j,1,3)
        endif
        if(nres.gt.4) then
          gcart(j,2)=gcart(j,2)+gloc(2,icg)*dphi(j,1,5)
        endif	  		
       enddo
c  If there are only five residues       
       if(nres.eq.5) then
         do j=1,3
           gcart(j,3)=gcart(j,3)+gloc(1,icg)*dphi(j,3,4)+gloc(2,icg)*
     &     dphi(j,2,5)+gloc(nres-1,icg)*dtheta(j,2,4)+gloc(nres,icg)*
     &     dtheta(j,1,5)
         if(itype(3).ne.10) then
      	   gcart(j,3)=gcart(j,3)+gloc(ialph(3,1),icg)*
     &	   dalpha(j,2,3)+gloc(ialph(3,1)+nside,icg)*domega(j,2,3)
         endif
      	 if(itype(4).ne.10) then
      	   gcart(j,3)=gcart(j,3)+gloc(ialph(4,1),icg)*
     &	   dalpha(j,1,4)+gloc(ialph(4,1)+nside,icg)*domega(j,1,4)
         endif
      	enddo
       endif
c    If there are more than five residues
      if(nres.gt.5) then 	 	     	   
        do i=3,nres-3
         do j=1,3
          gcart(j,i)=gcart(j,i)+gloc(i-2,icg)*dphi(j,3,i+1)
     &    +gloc(i-1,icg)*dphi(j,2,i+2)+
     &    gloc(i,icg)*dphi(j,1,i+3)+gloc(nres+i-4,icg)*dtheta(j,2,i+1)+
     &    gloc(nres+i-3,icg)*dtheta(j,1,i+2)
          if(itype(i).ne.10) then
           gcart(j,i)=gcart(j,i)+gloc(ialph(i,1),icg)*dalpha(j,2,i)+
     &     gloc(ialph(i,1)+nside,icg)*domega(j,2,i)
          endif
          if(itype(i+1).ne.10) then
           gcart(j,i)=gcart(j,i)+gloc(ialph(i+1,1),icg)*dalpha(j,1,i+1)
     &     +gloc(ialph(i+1,1)+nside,icg)*domega(j,1,i+1)
          endif
         enddo
        enddo
      endif 	
c  Setting dE/ddnres-2       
      if(nres.gt.5) then
         do j=1,3
           gcart(j,nres-2)=gcart(j,nres-2)+gloc(nres-4,icg)*
     &	   dphi(j,3,nres-1)+gloc(nres-3,icg)*dphi(j,2,nres)
     &     +gloc(2*nres-6,icg)*
     &     dtheta(j,2,nres-1)+gloc(2*nres-5,icg)*dtheta(j,1,nres)
          if(itype(nres-2).ne.10) then
              gcart(j,nres-2)=gcart(j,nres-2)+gloc(ialph(nres-2,1),icg)*
     &	      dalpha(j,2,nres-2)+gloc(ialph(nres-2,1)+nside,icg)*
     &        domega(j,2,nres-2)
          endif
          if(itype(nres-1).ne.10) then
             gcart(j,nres-2)=gcart(j,nres-2)+gloc(ialph(nres-1,1),icg)*
     &	     dalpha(j,1,nres-1)+gloc(ialph(nres-1,1)+nside,icg)*
     &       domega(j,1,nres-1)
          endif
         enddo
      endif 
c  Settind dE/ddnres-1       
       do j=1,3
        gcart(j,nres-1)=gcart(j,nres-1)+gloc(nres-3,icg)*dphi(j,3,nres)+
     &	gloc(2*nres-5,icg)*dtheta(j,2,nres)
        if(itype(nres-1).ne.10) then
          gcart(j,nres-1)=gcart(j,nres-1)+gloc(ialph(nres-1,1),icg)*
     &	  dalpha(j,2,nres-1)+gloc(ialph(nres-1,1)+nside,icg)*
     &    domega(j,2,nres-1)
        endif
        enddo
c   The side-chain vector derivatives
        do i=2,nres-1
         if(itype(i).ne.10) then	
            do j=1,3	
              gxcart(j,i)=gxcart(j,i)+gloc(ialph(i,1),icg)*dalpha(j,3,i)
     &        +gloc(ialph(i,1)+nside,icg)*domega(j,3,i)
            enddo
         endif	    
       enddo	 	     	  					  		     				 		    	           	
      return
      end