Dear Prof. Blaha
Thanks, the idea is to absorb molecules on surfaces, so in this case the
problem will not occur.
I used PRATT but without any success.
Thanks again.
Ricardo
-------------------------------------------------------------------------
Dr. Ricardo Faccio
Prof. Adjunto de F?sica
Mail: Cryssmat-Lab., C?tedra de F?sica, DETEMA
Facultad de Qu?mica, Universidad de la Rep?blica
Av. Gral. Flores 2124, C.C. 1157
C.P. 11800, Montevideo, Uruguay.
E-mail: rfaccio at fq.edu.uy
Phone: 598 2 924 98 59
598 2 929 06 48
Fax: 598 2 9241906
Web: http://cryssmat.fq.edu.uy/ricardo/ricardo.htm
---------------------------------------------------------------------------------
----- Original Message -----
From: "Peter Blaha" <pbl...@theochem.tuwien.ac.at>
To: "A Mailing list for WIEN2k users" <wien at zeus.theochem.tuwien.ac.at>
Sent: Monday, August 02, 2010 11:40 AM
Subject: Re: [Wien] mBJ potential for molecules?
mBJ was designed for solids and it could well be that for a molecules the
procedure
to determine a proper "c"-value (average of grad rho/rho) does not work and
you get
unphysical values due to the vacuum region.
In such a case I can only recommend to remove case.in0_grr, and set
a proper grad rho/rho value in case.grr yourself.
A good estimate would be to set it to a similar value as a "similar"
bulk-system
(eg. diamond) would have.
Also: Make sure you modified case.inm and set PRATT mixing !
Ricardo Faccio schrieb:
> Dear users
>
> I've been working on the isolated molecule catechol
> (http://en.wikipedia.org/wiki/Catechol) in order to see how mBJ affects
> its HOMO-LUMO gap.
>
> The initialization and convergence at GGA-PBE level went fine, obtaining a
> energy gap of 4.0 eV in concordance with other DFT codes.
>
> Afther this I proceeded in order to incorporate the modified Becke-Johnson
> potential (MBJ), but I found several problems in determining the position
> of the Fermi level. What we see is a clear problem of finding enough
> eigenvalues, which arelower than the number of valence electrons.
> Therefore we proceed according to the userguide by:
> -changing the Fermi-Method (tetra, gauss and temp) -> error persist
> - changing Rmt to similar values increasing the lmax to12 -> error persist
> - increasing energy window in case.klist and case.in1c in order to catch
> the lost eigenvalues -> error persist
> It seems to be a problem on a big change introduced by the mBJ potential
> which induces important divergences iat the lapw1.
>
> ######################
>
> case.output1up
> ######################
> EIGENVALUES ARE:
> 1.4443359 1.4892578 1.8037109 1.8486328 1.8486328
> 1.8935547 1.9384766 1.9384766
> 1923 EIGENVALUES BELOW THE ENERGY -9.00000
> ********************************************************
> The problem always occurs in the first cycle of the mBJ procedure after
> lapw1, with few eigenvalues as you can see.
>
> I succeed applying this methodology to bulk systems such as TiO2.
>
> Any suggestion?
>
> Best regards
>
> Ricardo
>
>
> -------------------------------------------------------------------------
> Dr. Ricardo Faccio
> Prof. Adjunto de F?sica
> Mail: Cryssmat-Lab., C?tedra de F?sica, DETEMA
> Facultad de Qu?mica, Universidad de la Rep?blica
> Av. Gral. Flores 2124, C.C. 1157
> C.P. 11800, Montevideo, Uruguay.
> E-mail: rfaccio at fq.edu.uy <mailto:rfaccio at fq.edu.uy>
> Phone: 598 2 924 98 59
> 598 2 929 06 48
> Fax: 598 2 9241906
> Web: http://cryssmat.fq.edu.uy/ricardo/ricardo.htm
> ---------------------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
--
P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671 FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at WWW:
http://info.tuwien.ac.at/theochem/
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