Subject: Re: CCL:Atomic charges ...

From: Arvydas Tamulis <[email-masked]>
Date: Wed, 24 Apr 2002 15:44:56 +0200 (EET)

Dear Professor Spanget-Larsen,

Thank you for your comment on my mistake that arrive from my text
concerning HF-TD calculation analysis.
In any case, I wanted to say that in G98 DFT-TD the absolute values of
atomic charge change have not any physical meaning and can not be interpreted
as electron density amount transfer during excitation.

The main question of my former letter was: what it is the algorithm of
charge transfer in ABINIT DFT-TD ?

I have just received response from Professor Gonze, who is one of authors
of ABINIT:

No analysis of static charges is yet available in ABINIT. The reason
is simple: we use a plane-wave basis set, for which there is no
such concept as a Mulliken population analysis. We are now implementing
Hirshfeld analysis, then Bader analysis, but it will take some time.

Best regards, Arvydas Tamulis
**********************
 On Wed, 24 Apr 2002, Jens Spanget-Larsen wrote:

> Arvydas Tamulis:
>
> > .. As you know that in
> > Gaussian 98 DFT-TD atomic charges in excited states are calculating
> > using one-particle electron densities and atomic charges in the
> > ground state are calculating using HF electron density.
>
> Dear Arvydas,
> just one comment: It is not true that the ground state atomic charges
> obtained by a G98 TD-DFT calculation are derived from a Hartree-Fock
> (HF) electron density. The printed ground state charges are the
> results of a Mulliken population analysis performed with the DFT
> Kohn-Sham molecular orbitals.
>
> Yours, Jens >--<
>
> NB! Please note new mail address: <[email-masked]>
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