[gmx-users] Langevin dynamics

[Berk Hess]

>From: "syma" <syma.khalid at bioch.ox.ac.uk>
>Reply-To: syma.khalid at bioch.ox.ac.uk,Discussion list for GROMACS users 
><gmx-users at gromacs.org>
>To: "'Discussion list for GROMACS users'" <gmx-users at gromacs.org>
>Subject: [gmx-users] Langevin dynamics
>Date: Tue, 4 Jul 2006 11:06:35 +0100
>
>Hi,
>
>I am still trying to do Langevin dynamics in gromacs- does anyone know 
>(ball
>park) what would be reasonable values to use for the frictional term when
>simulating helical peptides in solution?

You did not give enough information.

Are you using explicit or implicit solvent?

With implicit solvent you can use Stokes law to estimate the value.
But Gromacs does not come with an implicit solvent force field.
Any explicit solvent force field will give completely wrong results
if you just leave out the solvent.

Berk.