[DFTB-Plus-User] Cell Parameters Optimization

Benjamin Hourahine benjamin.hourahine at strath.ac.uk
Mon Jul 7 11:22:48 CEST 2008


At the moment, derivatives with respect to the lattice vectors are partly
implemented and being tested, but will hopefully be ready for the 1.2 release. 
The contributions from the long range terms (SCC and dispersion) and the 
momentum part of the virrial still have to be implemented.

Cheers

Ben

    Dr. B. Hourahine, Department of Physics, SUPA, University of Strathclyde,
      John Anderson Building, 107 Rottenrow, Glasgow G4 0NG, United Kingdom
    Ph +44 141 548 2325 FAX +44 141 552 2891 benjamin.hourahine at strath.ac.uk

The University of Strathclyde is a Scottish registered charitable body, number SC015263




-----Original Message-----
From: dftb-plus-user-bounces at dftb-plus.info on behalf of Victor Milman
Sent: Fri 04/07/2008 12:42
To: User list for DFTB+ related questions
Subject: Re: [DFTB-Plus-User] Cell Parameters Optimization
 
Dear Ben,

Do you have a feeling for when such a development could take place? In
particular, there are two slightly separate issues - stress calculation and
cell optimization. If the first part is done, one can plug DFTB+ into
existing optimizers and do some useful things including NPT MD, so there is
a lot of value in doing just that. Is stress project currently under
development, are we talking about the scale of months or years?

All the best

On Thu, Jul 3, 2008 at 9:09 AM, Benjamin Hourahine <
benjamin.hourahine at strath.ac.uk> wrote:

> Hello Marcelo,
>
> at the moment cell parameter optimisation isn't implemented, but
> is on the planned feature list for the code.
>
> Regards
>
> Ben
>
>    Dr. B. Hourahine, Department of Physics, SUPA, University of
> Strathclyde,
>      John Anderson Building, 107 Rottenrow, Glasgow G4 0NG, United Kingdom
>    Ph +44 141 548 2325 FAX +44 141 552 2891
> benjamin.hourahine at strath.ac.uk
>
> The University of Strathclyde is a Scottish registered charitable body,
> number SC015263
>
>
>
>
> -----Original Message-----
> From: dftb-plus-user-bounces at dftb-plus.info on behalf of Marcelo Zimmer
> Sent: Wed 02/07/2008 20:01
> To: dftb-plus-user at dftb-plus.info
> Subject: [DFTB-Plus-User] Cell Parameters Optimization
>
> Hi DFTB+ users,
>
> I'm new on DFTB+ and I'm trying to run some tests on periodic systems,
> however I couldn't find any flag for cell parameters optimization and I
> could notice that they are don't change in any of my calculations. Is this
> feature implemented on DFTB+ or do I have to perform such optimization by
> manually varying those parameters in order to minimize, for instance the
> c/a
> ratio for hexagonal cells?
>
> Thank you in advance,
>
> Marcelo Zimmer
>
>
>
> ===================================================
> Marcelo Zimmer S. Flores
> (PhD Physics Student)
>
> Address:
> Universidade Estadual de Campinas - UNICAMP
> Instituto de Fisica Gleb Wataghin - IFGW
> Grupo de Solidos Organicos e Novos Materiais - GSONM
> Departamento de Fisica Aplicada (DFA) - Room 61
> Campinas - Sao Paulo - Brazil
> 13083-970
> Caixa Postal: 6165
> zimmer at ifi.unicamp.br
> ===================================================
>
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-- 
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Victor Milman                 Senior Fellow
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