[gmx-users] calculation the force of interaction

[David van der Spoel]

Mark Abraham wrote:
>>   Hello,
>>
>> In the same context that my question of yesterday (see the post at the
>> end of this message), I'm interested in calculating the force of the
>> interaction between lipids and solvent. More precisely, I want to
>> calculate the norm of the force vector related to all non-bonded
>> interactions (LJ+Coulomb). Is it possible to do that in Gromacs without
>> severely hacking the code? I have searched in the mailing-list but have
>> found only few posts about that, all on the developer mailing-list.
> 
> I wrote some code that did something similar to this in order to find RMS
> errors in (the norm of?) nonbonded forces when optimizing PME parameters.
> It's been a while since I looked at it, and I'm skeptical that group-wise
> decomposition would be easy to hack in, but I'll have another look at what
> the code did.

Indeed, forces would be quite a bit of work, but energies (including 
PME) is possible. The question is what it means.

Maybe you want to look into pull code as well.


-- 
David van der Spoel, Ph.D.
Molec. Biophys. group, Dept. of Cell & Molec. Biol., Uppsala University.
Box 596, 75124 Uppsala, Sweden. Phone:	+46184714205. Fax: +4618511755.
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://folding.bmc.uu.se