[Wannier] dis_project ZGESVD error

Brad Malone brad.malone at gmail.com
Sat Dec 10 00:51:45 CET 2011


Jonathan and Nicola,

Thanks for the suggestions. I tried different libraries on the machine I
was using and was not able to avoid the problem. However, I found out that
if I use pw2wannier and get the .amn, .mmn, and .eig files, take those to
my local machine, and run Wannier as a standalone program rather than as a
library, that everything is easily wannierized.

So I suppose this suggests that either the difference is the math libraries
I'm using on my local machine, some subtlety between the Wannier standalone
program and running as a library, or another issue possibly related to the
code which calls Wannier as a library.

Anyway, I had the Wannier standalone program write out the two Wannier
rotation U matrices, multiplied them together, and then had my original
code use that rotation matrix and continue on with its work. Tests on
pressures for which both methods work yield the same answer so I am content
with this.

Thanks again,
Brad

On Thu, Dec 8, 2011 at 12:40 AM, <wannier-request at quantum-espresso.org>wrote:

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> Today's Topics:
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>   1. Re: dis_project ZGESVD error (Jonathan Yates)
>   2. Re: dis_project ZGESVD error (Nicola Marzari)
>
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> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 7 Dec 2011 11:11:03 +0000
> From: Jonathan Yates <jonathan.yates at materials.ox.ac.uk>
> Subject: Re: [Wannier] dis_project ZGESVD error
> To: "wannier at quantum-espresso.org" <wannier at quantum-espresso.org>
> Message-ID: <7F921E85-8DAB-4ED3-BB90-E396772FCFA7 at materials.ox.ac.uk>
> Content-Type: text/plain; charset="us-ascii"
>
>
> On 6 Dec 2011, at 19:25, Brad Malone wrote:
>
> > Hi, I am using wannier in library mode for calculations on a system as a
> function of pressure. I am able to successfully wannierize the system for
> 20,25,30, and 40 GPa with essentially no change in the p.win file except
> for a slight change to the frozen window range (to account for the increase
> in the bandwidth as a function of pressure).
> >
> > However, when I try to do it for 50 GPa, for the same system and
> parameters, I get the error:
> >
> >
> >                   Unitarised projection of Wannier functions
> >                   ------------------------------------------
> >   A_mn = <psi_m|g_n> --> S = A.A^+ --> U = S^-1/2.A
> >   In dis_project...  ERROR: IN ZGESVD IN dis_project
> >  K-POINT NKP=            1  INFO=            7
> > Exiting.......
> > dis_project: problem in ZGESVD 1
> >
> > I was originally using 'random' projections, since that is what has
> worked for me for the previous pressures. When I saw this message I tried
> fiddling with the projections, the number of wannier functions, and the
> number of input bands, but nothing changed (except changing the number of
> wannier functions changes the value for INFO).
>
> Brad,
>
> The error means that that singular value decomposition has failed to
> converge. It's being used to compute the initial guess for the unitary
> rotation.
>
>  I've never encountered this error before, and from your description it is
> not at all obvious what might cause it. Perhaps it is worth trying a
> different set of math libraries. (eg if you are using mkl, try the netlib
> lapack).
>
>  Otherwise, if no-one else has a solution, you could send the files (win,
> eig, amn, mmn) to me.
>
>  Jonathan
>
>
>
>
> --
> Department of Materials, University of Oxford, Parks Road, Oxford, OX1
> 3PH, UK
> tel: +44 (0)1865 612797                http://users.ox.ac.uk/~oums0549/
>
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 07 Dec 2011 13:19:14 +0100
> From: Nicola Marzari <nicola.marzari at epfl.ch>
> Subject: Re: [Wannier] dis_project ZGESVD error
> Cc: "wannier at quantum-espresso.org" <wannier at quantum-espresso.org>
> Message-ID: <4EDF59C2.6040606 at epfl.ch>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
>
> Dear Brad,
>
>
> a guess is that your random projections, projected on the kohn-sham
> manifold, end up having a couple of them that are almost linearly
> dependent.
>
> Can you choose instead a regular mesh of centers for the projections,
> or maybe something slightly more physical?
>
> If your system is large, you could try the gamma sampling only -
> that typically does not need projections, and you could use the results
> as centers for the next set of projections?
>
>                nic
>
>
> On 12/7/11 12:11 PM, Jonathan Yates wrote:
> >
> > On 6 Dec 2011, at 19:25, Brad Malone wrote:
> >
> >> Hi, I am using wannier in library mode for calculations on a system as
> a function of pressure. I am able to successfully wannierize the system for
> 20,25,30, and 40 GPa with essentially no change in the p.win file except
> for a slight change to the frozen window range (to account for the increase
> in the bandwidth as a function of pressure).
> >>
> >> However, when I try to do it for 50 GPa, for the same system and
> parameters, I get the error:
> >>
> >>
> >>                    Unitarised projection of Wannier functions
> >>                    ------------------------------------------
> >>    A_mn =<psi_m|g_n>  -->  S = A.A^+ -->  U = S^-1/2.A
> >>    In dis_project...  ERROR: IN ZGESVD IN dis_project
> >>   K-POINT NKP=            1  INFO=            7
> >> Exiting.......
> >> dis_project: problem in ZGESVD 1
> >>
> >> I was originally using 'random' projections, since that is what has
> worked for me for the previous pressures. When I saw this message I tried
> fiddling with the projections, the number of wannier functions, and the
> number of input bands, but nothing changed (except changing the number of
> wannier functions changes the value for INFO).
> >
> > Brad,
> >
> > The error means that that singular value decomposition has failed to
> converge. It's being used to compute the initial guess for the unitary
> rotation.
> >
> >   I've never encountered this error before, and from your description it
> is not at all obvious what might cause it. Perhaps it is worth trying a
> different set of math libraries. (eg if you are using mkl, try the netlib
> lapack).
> >
> >   Otherwise, if no-one else has a solution, you could send the files
> (win, eig, amn, mmn) to me.
> >
> >   Jonathan
> >
> >
> >
> >
>
>
> --
>
> ----------------------------------------------------------------------
> Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
>
>
> ------------------------------
>
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