GGA functional and "nlo" calculations

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roginovicci
Posts: 75
Joined: Thu Dec 02, 2010 10:36 pm

GGA functional and "nlo" calculations

Post by roginovicci » Thu Mar 24, 2011 9:19 am

I'm trying to study static non-linear properties on Hg2Cl2 crystals. I'm using GGA psevdopotential with ixc = 11 (GGA, Perdew-Burke-Ernzerhof GGA functional) set in input file. The abinit fails to start complying on error using ixc=11. It seems it is forbidden to use prepanl=1 with isc=11 and opdriver=5 is not allowed too. Is it possible to run "nlo" calculations with GGA pseudopotentials?

Boris
Posts: 128
Joined: Tue Feb 16, 2010 10:13 am
Location: France

Re: GGA functional and "nlo" calculations

Post by Boris » Thu Mar 24, 2011 3:54 pm

Hi

What is your value of iscf?

Boris
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Boris Dorado
Atomic Energy Commission
France
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roginovicci
Posts: 75
Joined: Thu Dec 02, 2010 10:36 pm

Re: GGA functional and "nlo" calculations

Post by roginovicci » Thu Mar 24, 2011 10:24 pm

Thank you for reply, Boris! Answering on your question I may say I use pulay mixing of the potential iscf=7.

I found thread in this forum viewtopic.php?f=10&t=935
They say it is not possibly to perform "nlo" with GGA. Is this the case?

Boris
Posts: 128
Joined: Tue Feb 16, 2010 10:13 am
Location: France

Re: GGA functional and "nlo" calculations

Post by Boris » Thu Mar 24, 2011 10:27 pm

Hi

I was just checking if you were using the PAW method rather than the PP approach. Seems that you don't.

Then it is very likely that it is not possible to do that with GGA functionals.

Boris
----------------------------------------------------------
Boris Dorado
Atomic Energy Commission
France
----------------------------------------------------------

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jzwanzig
Posts: 504
Joined: Mon Aug 17, 2009 9:25 am

Re: GGA functional and "nlo" calculations

Post by jzwanzig » Wed Mar 30, 2011 3:14 pm

Hi,
according to the code (chkinp.F90), the following values of ixc are the only ones allowed for prepanl:

0, 3, 7, 8.

They are described in the input variables documentation; 0 means no XC; 3 and 7 are two parameterizations of LDA; and 8 is the exchange only part of 7.
Josef W. Zwanziger
Professor, Department of Chemistry
Canada Research Chair in NMR Studies of Materials
Dalhousie University
Halifax, NS B3H 4J3 Canada
jzwanzig@gmail.com

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