[gmx-users] question about force field parameter

[Mark Abraham]

Zhanglin Ni wrote:
> Dear all
> I am a little confused with some force field parameter library. for example

Whether and how this makes sense depends on the context, which you need 
to tell us, since we are not going to go looking and guessing for you. :-)

> #define gd_26     0.000       2.93          3

This defines a preprocessor macro called gd_26 that replaces each 
instance of that token string with the three numbers above.

> ; -CH2-S-       0.7

This is a comment line.

> dihedral is supposed to be i j k l 4 atoms , why, for example, the case 
> above has only 2 atoms.

You may need to consider the effect of that macro in the context where 
it is used.

Mark