[gmx-users] g_potential: better precision

[David van der Spoel]

이 선주 wrote:
> Dear All,
> 
> I am trying to calculate membrane potential from the charge density. I 
> have calculated membrane potential from the charge density profile 
> obtained from g_potential function. But I've got unmatched potential 
> between block-averaged(10 ns *6) potential and the potential from the 
> whole trajectory (60 ns *1). Roundoff error in charge density 
> calculation was the reason for the unmatched potential. So I am 
> wondering if anyone can guide me so that I can increase the precision of 
> the charge density in the output file of g_potential. Any suggesion will 
> be appreciated!
> 
You  get more averaging in longer stretches of trajectory. As long as
your interface doesn't move both results should be valid.
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://folding.bmc.uu.se
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