double precision function funmin ( xmer, nmer )
	implicit none
	integer nmer
	double precision xmer(nmer)

      include 'sizes.i'
      include 'files.i'
      include 'inform.i'
      include 'iounit.i'
      include 'math.i'
      include 'omega.i'
      include 'zcoord.i'
      include 'usage.i'

	integer mnat, i, ik, ixyz, nunit
	double precision energy, fl

	integer ifirst
	save ifirst
	data ifirst / 0 /

	mnat = (nmer+6)/3
	if (ifirst.eq.0) then
		ifirst = 1
		call initial
		call getint
		call mechanic
cc		call initrot
		nomega = 0
		do i=4,mnat
			if (iz(4,i).eq.0) then
				nomega = nomega+1
				iomega(1,nomega) = iz(1,i)
				iomega(2,nomega) = iz(2,i)
				dihed(nomega) = ztors(i)/radian
				zline(nomega) = i
			end if
		end do
		do i=1,mnat
			use(i) = .true.
		end do
cc			write (*,*) 'nomega=',nomega
cc			do i=1,nomega
cc				write (*,*) 'i iomega=',i,iomega(1,i),iomega(2,i)
cc				write (*,*) 'i zline  ',i,zline(i),dihed(i)
cc			end do
cc		do i=1,mnat
cc			write (*,*) 'zbond ',i,zbond(i)
cc			write (*,*) 'zang  ',i,zang(i)
cc			write (*,*) 'ztors ',i,ztors(i)
cc		end do
		ik = 0
		do i=2,mnat
			ik = ik+1
			call setx1(ik,zbond(i))
		end do
		do i=3,mnat
			ik = ik+1
			call setx1(ik,zang(i))
		end do
		do i=4,mnat
			ik = ik+1
			call setx1(ik,ztors(i))
		end do
	end if
	zbond(1) = 0.
	zang(1) = 0.
	zang(2) = 0.
	ztors(1) = 0.
	ztors(2) = 0.
	ztors(3) = 0.
	ik = 0
	do i=2,mnat
		ik = ik+1
		zbond(i) = xmer(ik)
	end do
	do i=3,mnat
		ik = ik+1
		zang(i) = xmer(ik)
	end do
	do i=4,mnat
		ik = ik+1
		ztors(i) = xmer(ik)
	end do
cc      do i = 1, nomega
cc         dihed(i) = ztors(zline(i)) / radian
cc      end do                                                                    
	call makexyz
cc	call gradrot(energy,derivs)

	funmin = energy()

	call getfla(1,fl)
	if (fl.ne.0.) then
		fl = 0.
		call setfla(1,fl)
		ixyz = nunit()
		if (ixyz.eq.-1) stop 'ERR: NO FREE UNIT'
		call prtxyz(ixyz)
	end if

	end

	subroutine granal ( nmer, xmer, gmer )
	implicit none
	integer nmer
	double precision xmer(nmer), gmer(nmer)

      include 'sizes.i'
      include 'omega.i'
      include 'zcoord.i'

	integer mnat, i, ik, ioff
	double precision energy
	double precision derivs(maxrot), radian

	do i=1,nmer
		gmer(i) = 0.
	end do

	mnat = (nmer+6)/3
	zbond(1) = 0.
	zang(1) = 0.
	zang(2) = 0.
	ztors(1) = 0.
	ztors(2) = 0.
	ztors(3) = 0.
	ik = 0
	do i=2,mnat
		ik = ik+1
		zbond(i) = xmer(ik)
	end do
	do i=3,mnat
		ik = ik+1
		zang(i) = xmer(ik)
	end do
	do i=4,mnat
		ik = ik+1
		ztors(i) = xmer(ik)
	end do
cc      do i = 1, nomega
cc         dihed(i) = ztors(zline(i)) / radian
cc      end do                                                                    
	call makexyz
	call gradrot(energy,derivs)

	ioff = 2*mnat-6
	radian = 57.29577951308232088d0
	do i=1,nomega
		gmer(zline(i)+ioff) = derivs(i)/radian
	end do

	end