Re: COMmotion -- is it a good practice to turn it on for a restart?

From: Brian Radak (
Date: Tue Mar 19 2019 - 17:03:02 CDT

This default mostly exists due to a pathology of PME that causes spurious
center of mass drift. However, the effects compound with stochastic
integrators like Langevin dynamics (which also causes center of mass

You are correct that if you want as close a continuation from your initial
structure as possible that you should set COMmotion on. For example this is
the only way to get an accurate NVE restart.

On Tue, Mar 19, 2019, 5:31 PM Homeo Morphism <>

> COMmotion is by default set to no or off. Which, from what I gather,
> results in initial velocities being re-scaled to make COM appear stationary
> before every restart. This probably makes sense if your restart is a start
> of a new production run from an equilibration phase. But what if I restart
> to continue a production trajectory? Wouldn't I want the system to preserve
> the overall direction it had at the very end of the previous step? In other
> words, should I turn COMmotion on?
> Thanks,
> Oleg

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