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Re: [abinit-forum] TPSS implementation in abinit (or nanoquantaxc?)

From: "Anglade Pierre-Matthieu" <anglade@gmail.com>
To: forum@abinit.org
Subject: Re: [abinit-forum] TPSS implementation in abinit (or nanoquantaxc?)
Date: Tue, 22 Aug 2006 08:39:02 +0200
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Hi,

Have you tryed a look at the different functionnals readily available
in abinit ? For instance I have heard that using "ixc=9" may give some
much more accurate results.

regards

PMA

On 8/21/06, fer@tiziano.phys.washington.edu
<fer@tiziano.phys.washington.edu> wrote:

Hi..

As I have probably mentioned here before, we have been working on
calculating EXAFS Debye-Waller factors using the dynamical matrices generated
by abinit. The whole approach works quite well, but we are not totally
satisfied by the results we get from either LDA (PW92) or GGA (PBE). For us
it is quite crucial getting the interatomic force constant accurately. We
have found that they depend a lot on the crystal lattice that we use, and
therefore we need to be able to find a way to realiably predict both the
crystal lattice and the force constants simultaneously. Its seems that
neither PW92 nor PBE can do this.

We got in contact with John Perdew and he suggested we try the meta-GGA TPSS
and we have tried to do so with the implementation already available in
Gaussian 03. for reasons I don't what to discuss here, this implementation
has several drawbacks when it comes to solid states.

Therefore, I was wondering if anyone has implemented TPSS into abinit
already. I did a search on the source and found that nanoquantaxc has TPSS,
but I really don't know how to integrate it into my binaries nor how to call
it. Any experience, instructions, etc, etc, in this regards would be greatly
welcome.

Best regards and thanks in advance, Fer.

Ubi dubium ibi libertas.
*******************************************************************************
Fernando D. Vila Voice (206)543-9697
Department of Physics Fax (206)685-0635
University of Washington E-mail fdv@u.washington.edu
Seattle, WA 98195, USA WWW http://faculty.washington.edu/fdv
*******************************************************************************

--
Pierre-Matthieu Anglade

TPSS implementation in abinit (or nanoquantaxc?), fer, 08/21/2006
- Re: [abinit-forum] TPSS implementation in abinit (or nanoquantaxc?), Anglade Pierre-Matthieu, 08/22/2006
  - Re: [abinit-forum] TPSS implementation in abinit (or nanoquantaxc?), Andrew M. Rappe, 08/22/2006
- Re: [abinit-forum] TPSS implementation in abinit (or nanoquantaxc?), Xavier Gonze, 08/31/2006