[gmx-users] epsilon_surface mdp parameter

[Erik Lindahl]

Kristina Nicole Woods wrote:

> Hello:
>
> I've noticed that there is an epsilon_surface mdp option in Gromacs.  Does
> this represent the dipole at the surface of the system when using PME?
> When a value of epsilon_surface = 0 (which is the default parameter
> value) is used what does this actually mean?
>
> Thank you,
>
> Kristina :)

Hi Kristina,

Yes, it is the standard dipole correction - when it is zero it is simply
turned off.
We might actually just have found a bug in the case when it's turned on
(the effect is usually very small, though) - I'm checking that right now...
It doesn't
affect the standard case when eps=0, though.

Cheers,

Erik