AMBER Archive (2002)

Subject: Re: NON-BONDED INTERACTION

From: David A. Case (case_at_scripps.edu)
Date: Tue Oct 01 2002 - 10:28:00 CDT

On Tue, Jul 30, 2002, Rosalia Pascual wrote:
>
> I work with ntb = 0 ( no periodicity althoug I have used the
> SolvateCap WATBOX216 option in xleap ), and it seems to me that despite
> this direct sum nonbonded list from ewald calculations are used. I
> don`t understand why at the end of the mdout file appears:
>
> | Direct Ewald time 119.89 (98.29% of Ewald)

The "direct" part of an Ewald calculation is just the ordinary type of
non-bonded calculation you are probably used to. This part of the calculation
is done whether or not there is periodicity, and whether or not the
"reciprocal" part of the Ewald sum is carried out. The label may be somewhat
misleading, but it does not imply that there is any Ewald (or PME) calculation
being carried out.

..hope this helps...dac 

-- 

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