subroutine char SEGMENTS
define class charge by topo sele segm name SEGMENTS end
set class sele atom name S* .and. by bond atom name S* \
     .a segm name SEGMENTS end = S
defin class charge \
     sele by resi atom name HT* .a segm name SEGMENTS .a .n resi name PRO end \
     by topo resi NTER
defin class charge \
     sele by resi atom name HT* .a segm name SEGMENTS .a resi name PRO end \
     by topo resi NTPR
defin class charge \
     sele by resi atom name OT* .a segm name SEGMENTS end \
     by topo resi COTR

defin class charge \
     sele by resi atom name OXT .a segm name SEGMENTS end \
     by topo resi CTER

defin class charge \
	sele by resi atom name H5T .a segm name SEGMENTS end \
	by topo resi 5TER
defin class charge \
	sele by resi atom name H3T .a segm name SEGMENTS end \
	by topo resi 3TER

define bond angle init select segm name SEGMENTS end by auto 
define dihe by topo init select segm name SEGMENTS end
define impr by topo init select segm name SEGMENTS end ! check
define impr dihe \
	select by resi atom name HT* .a segm name SEGMENTS end \
	resi NTER
define impr dihe \
	select by resi atom name OT* .a segm name SEGMENTS end \
	by topo resi CTER

define impr dihe \
	select by resi atom name H5T .a segm name SEGMENTS end \
	resi 5TER
define impr dihe \
	select by resi atom name H3T .a segm name SEGMENTS end \
	by topo resi 3TER

define dihe impr sele by resi clas name XXXX end by guess 

define init ring sele segm name SEGMENTS end

define hbond force FORCE_HBON hbond dist DIST_HBON \
	sele segm name SEGMENTS end 

defin pair force 300. pair dist 0. sele all end

return

!set class sele atom name HT% end HC
!set class sele atom name N* .and. by bond atom name HT* end NH3
!set class sele atom name OT% end OC