logical lprn /.false./, lprn1 /.false./
etheta=0.0D0
do i=ithet_start,ithet_end
logical lprn /.false./, lprn1 /.false./
etheta=0.0D0
do i=ithet_start,ithet_end
c print *,i,itype(i-1),itype(i),itype(i-2)
if ((itype(i-1).eq.ntyp1).or.itype(i-2).eq.ntyp1
& .or.itype(i).eq.ntyp1) cycle
c print *,i,itype(i-1),itype(i),itype(i-2)
if ((itype(i-1).eq.ntyp1).or.itype(i-2).eq.ntyp1
& .or.itype(i).eq.ntyp1) cycle