[gmx-users] pb with temperature in bd (2)

[Berk Hess]

>From: "BON Michael" <michael.bon at cea.fr>
>Reply-To: Discussion list for GROMACS users <gmx-users at gromacs.org>
>To: <gmx-users at gromacs.org>
>Subject: [gmx-users] pb with temperature in bd (2)
>Date: Tue, 3 Jul 2007 10:04:34 +0200
>
>
>I just wanted to add one thing to my previous mail, that may give some 
>insight to a skilled Gromacs user :
>when I replace bd with md or sd in the .mdp, the system is correctly 
>equilibrated with the required
>temperature. This problem of doubling temperature (ie 620 instead of 310) 
>occurs only with bd.

With Brownian dynamics there are no velocities.
Just as for the other integrators Gromacs stores the displacement in one 
timestep
divided by the timestep in the velocity field. From this the temperature
is determined, which is meaningless. The real temperature is the temperature
you set in the mdp file.

Berk.

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