AMBER Archive (2003)

Subject: Re: nasty npt md problem (fwd)

From: David A. Case (case_at_scripps.edu)
Date: Sun Mar 09 2003 - 23:58:58 CST

On Wed, Mar 05, 2003, amber_at_heimdal.compchem.ucsf.edu wrote:
>
> when i switch to npt md then there is a raise in density at a certain point
> followed by a drop and the simulation stops for ewald bomb reasons.

Do you know what the density should be? Is it ever close to being correct?

> obviously there is some vlimit exception.

Are you saying this because there are "vlimit" error messages? Or is it
obvious to you for some other reason? Can you look at what these system
is doing when the first vlimit messages occur?

Suggestions: 7 Ang. is a pretty short cutoff; try 9 to be safer. Run some
shorter simulations, stop right before bad things happen (density drops)
and see if anything looks funny.

..good luck...dac 

-- 

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David A. Case                     |  e-mail:      case_at_scripps.edu
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