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Re: gamma in langevin thermostat ver 3.3.1
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From: |
Rudolf Weeber |
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Subject: |
Re: gamma in langevin thermostat ver 3.3.1 |
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Date: |
Mon, 11 Nov 2019 10:32:36 +0100 |
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User-agent: |
Mutt/1.9.4 (2018-02-28) |
Hi Alex,
On Sun, Nov 10, 2019 at 03:42:56PM -0500, Alexander Afanasyev wrote:
> I am using a langevin thermostat in ver 3.3.1. I am confused what gamma is (a
> friction coefficient or collision frequency)?
> I remember someone answered this question two years ago, but it is still
> unclear if it was fixed in ver 3.3.1.
First of all, support for the TCL version has been terminated. It is strongly
recommended to use Espresso 4.1 for all current work.
In current versions of Espresso, gamma is the friction coefficient in the
Langevin eqn:
m x.. -gamma x. +F_random +F =0
However, this was different at some point. IIRc, gamma included some mass
dependence. I do not know when this changed.
Regards, Rudolf