From owner-chemistry@ccl.net Thu Nov 25 12:00:00 2010
From: "=?ISO-8859-1?Q?Ulf_Ekstr=F6m?= ulfek(~)few.vu.nl" <owner-chemistry()server.ccl.net>
To: CCL
Subject: CCL: Question on calculation of charge center of electrons in a molecule
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Date: Thu, 25 Nov 2010 17:58:25 +0100
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Sent to CCL by: =?ISO-8859-1?Q?Ulf_Ekstr=F6m?= [ulfek],[few.vu.nl]
On Thu, Nov 25, 2010 at 9:56 AM, Herbert Fruchtl
herbert.fruchtl-.-st-andrews.ac.uk <owner-chemistry .. ccl.net> wrote:
>
> Sent to CCL by: Herbert Fruchtl [herbert.fruchtl*_*st-andrews.ac.uk]
> I don't have time to look at the maths of it, but I think the centre of
> charge of the electron density should be identical to the centre of the
> Mulliken charges, which would be easy to calculate (analogous to the centre
> of mass).

This will not work, for example if you have a single centre basis set all
Mulliken charge would be on that center. What you should do is to compute
the dipole moment of the molecule and use that to work out the center
of charge.

Sincerely,
Ulf Ekstrom