[gmx-users] Forces

[K.A. Feenstra]

Nguyen Hoang Phuong wrote:
> 
> Dear All,
> 
> In the mdp options file, the nstfout is switched on and the total force
> acting on each atom is written out in the trajectory file. I would like to
> separate this total force into the internal forces (between the atoms of
> the solute) and the external forces (between the atoms of the solute and
> the atoms of solvent). Is there any option in GROMACS or will I have to
> change something in the force subroutine? Thanks.

No, there is no option (or default analysis tool) for it in Gromacs.
However, if I'm not mistaken you can use g_traj to extract the
force values from your trajectory and write it in ascii format,
so you could write a simple program or script yourself. Alternatively,
you can write a c-program using the template file that is provided
somewhere in the gromacs source tree.

You will in any case not need to modify the force subroutine, as 
all you would want is already present in the trajectory...


-- 
Groetjes,

Anton
 ________ ___________________________________________________________
|        | Anton Feenstra                                            |
| .      | Dept. of Pharmacochemistry - Vrije Universiteit Amsterdam |
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