[DFTB-Plus-User] Error: Failure in diagonalisation routine ZHEEVR, unable to complete Cholesky factorization of B 46

Ben Hourahine benjamin.hourahine at strath.ac.uk
Mon May 8 18:58:54 CEST 2017


Hello Lachlan,


the automated k-point grid correctly generates points without inversion
folding in this case, so something like


    KPointsAndWeights = SupercellFolding {
        6 0 0
        0 6 0
        0 0 6
        0.5 0.5 0.5
    }


is fine.

Regards

Ben


On 08/05/17 15:15, Lachlan Oberg wrote:
>
> Hello Bálint,
>
>
> Thanks for your quick reply, your solution works! Could I also ask a
> question regarding a paragraph in the SpinOrbit section of the manual
> (section 2.4.3, page 29):
>
>
> "For periodic systems, use of this keyword automatically prevents the
> folding by
>
> inversion normally used in SupercellFolding{}, but manually specified
> KPointsAndWeights should
> not be reduced by inversion."
>
> I took this to mean that manual k-point sampling should be used in
> spin orbit calculations, and this is the reason I used 2x2x2 sampling
> as it was quick to write out. Is this not a correct interpretation of
> that paragraph?
>
> Kind regards
> Lachlan
> ------------------------------------------------------------------------
> *From:* DFTB-Plus-User
> <dftb-plus-user-bounces at mailman.zfn.uni-bremen.de> on behalf of Bálint
> Aradi <aradi at uni-bremen.de>
> *Sent:* Monday, May 8, 2017 6:58:13 PM
> *To:* User list for DFTB+ related questions
> *Subject:* Re: [DFTB-Plus-User] Error: Failure in diagonalisation
> routine ZHEEVR, unable to complete Cholesky factorization of B 46
>  
> Dear Lachlan,
>
> > Regardless of the spin coupling constants I enter (with the exception of
> > non-zero values for the s orbital), I obtain the following error after
> > 10 geometry steps:
> >
> > -> Failure in diagonalisation routine ZHEEVR, unable to complete
> > Cholesky factorization of B     46
> >
> > Any ideas on what I can do to fix this? For reference, I am using the
> > si-band parameter set.
>
> Note, the siband parameter set is not meant for geomertry optimisation
> at all. It only contains the electronic parameterisation and a dummy
> spline. So, if you do geometry optimisation, it definitely ends up in a
> completely unphysical geometry, where the overlap becomes non-positive
> definite and therefore the diagonalization fails.
>
> By the way, a side note: You should use a better k-point set as 2x2x2
> for the primitive cell. Actually, if you k-point sampling is decent
> enough, you should see no forces on the atom, as those cancel out in a
> cubic structure...
>
> > Changing to the pbc parameter set, geometry convergence DOES occur.
> > However, after sampling along the k-lines L - G - X and using dp_bands,
> > I obtain the error:
> >
> >   File
> > "/apps/dftbp/1.3.1/lib/python2.7/site-packages/dptools/bandout.py", line
> > 69, in fromfile
> >     nkpt = len(eigvalarrays) / nspin
> > ZeroDivisionError: integer division or modulo by zero
> >
> > I assume this means I have to set nspin /= 0 somewhere, but I cannot
> > figure out how to do so.
>
> This is a bug, I am sorry for it. The dp_tools package is apparently not
> aware about the non-colinear output format. While we are fixing it, you
> can convert the band.out file using the following shell-command:
>
> sed 's/KPT[ ]*\([^ ]*\)/KPT \1 SPIN 1/g' band.out > band_fixed.out
>
> If you run dp_tools on band_fixed.out, it should work.
>
>   Best regards,
>
>   Bálint
>
> -- 
> Dr. Bálint Aradi
> Bremen Center for Computational Materials Science, University of Bremen
> http://www.bccms.uni-bremen.de/cms/people/b-aradi/
>
>
>
>
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-- 
      Dr. B. Hourahine, SUPA, Department of Physics,
    University of Strathclyde, John Anderson Building,
            107 Rottenrow, Glasgow G4 0NG, UK.
    +44 141 548 2325, benjamin.hourahine at strath.ac.uk

2013/4 THE Awards Entrepreneurial University of the Year
      2012/13 THE Awards UK University of the Year

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

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