kkk=0
c print *,'nnt=',nnt,' nct=',nct
do i=nnt,nct-3
+ if (itype(i).eq.ntyp1) cycle
do k=1,3
c(k,2*nres+1)=0.5d0*(c(k,i)+c(k,i+1))
enddo
do j=i+2,nct-1
do k=1,3
+ if (itype(j).eq.ntyp1) cycle
c(k,2*nres+2)=0.5d0*(c(k,j)+c(k,j+1))
enddo
if (dist(2*nres+1,2*nres+2).lt.rcomp) then