[gmx-users] Help wanted!

[Erik Lindahl]

david luo wrote:

> Dear gromacs users, i have a question, can i simulate water molecule
> under external electrical field? What kind of modification is needed
> to include the external electric field? Thanks
>
Well, it depends a little on the type of electric field you had in mind.
Constant fields are already supported - check the mdp options part of
the online manual for details.

There are also _options_ to use arbitrary combinations of harmonic
space- and time- dependent, but this is not yet implemented in the code
(it says so on the options page, too) since we've never had any use for
it yet...

If you want to hack around it should be fairly easy to implement any
field you want - the forces due to the field are applied in the routine
calc_f_el in the file src/mdlib/sim_util.c.

Cheers,

Erik