hell all:
i want to change some bonds force constants and bond lengths to do some
simulations. it seems that can be done by modifing FFg43a1bon.itp.
The CHARMM force field which i used before defined the force constant
with physical units Kcal/mol/A*A which almost in 10^2 orders. ( for
example the force constant of C-C is 240 ).
but in the FFg43a1bon.itp most force constant is in 10^(-7) orders ( for
example : #define gb_1 0.1000 1.5700e+07
; H - OA 750 )
From the Gromacs manual it seems that the pysical units of force constant
is KJ/mol/nm*nm
.even that i think the order is too far from that of CHARMM. so how to
convert CHARMM force constant into Gromos force field?
rgards
caoch
tokyo institute technology