[Pw_forum] PAW orthonormality and obtaining S|psi>

Holzwarth, Natalie natalie at wfu.edu
Sat Apr 16 16:21:44 CEST 2016


Dear Henry,
      In the PAW method, the atomic pseudo basis functions are not designed
to be orthogonal to each other, but  there is a "dual relationship"
<p_i|\tilde{\psi}_j>=\delta_{ij} with the projector function p_i.   One can
use the projector function to estimate the charge associated with an atomic
site within the augmentation sphere about that site.   (Some notes are
enclosed about this in case you are interested.  The main equations are
correct, but the programming details are no longer true.)    Paolo
Giannozzi programmed this into quantum espresso in version 5.3.0.
Perhaps this might suite your needs??   In order to use it you need to use
&projwfc:

  &projwfc
    pawproj= .true. ,   << new option
    outdir='$outd/',     << old options; change as appropriate
    prefix='$label',
    filpdos='pdos',
    Emin=-25.0, Emax=25.0, DeltaE=0.01,
    ngauss=0,  degauss=0.01
/

Sincerely, Natalie Holzwarth


N. A. W. Holzwarth                                       email:
natalie at wfu.edu
Department of Physics                                  web:
http://www.wfu.edu/~natalie
Wake Forest University                                 phone:
1-336-758-5510
Winston-Salem, NC 27109 USA                     office: Rm. 300 Olin
Physical Lab

On Fri, Apr 15, 2016 at 8:02 PM, Henry J Seeley <hseeley at uoregon.edu> wrote:

> Hello all,
>
> I'm currently trying to use Quantum Espresso to generate the
> eigenfunctions for bulk and slab systems of PbS, which I then plan on
> projecting onto one another to determine the relative surface or bulk
> character of specific slab states. I've generated my sample systems and
> have run the scf/nscf calculations, but I've hit some trouble with the
> eigenvectors obtained from 'pw_export.x'. I have a couple questions that I
> hope some of you may be able to answer. Of course all my input files will
> be attached.
>
> To my surprise I found that different eigenstates of the same system are
> NOT orthonormal (<psi_i|psi_i> ~= 0.75, abs(<psi_i|psi_j>) ~= 0.15). I've
> done some searching and determined this may have to do with the PAW
> psuedo-potentials I am using. Is the PAW method the problem here?
>
> In trying to troubleshoot this, I found that eigenstate orthonormality may
> be obtained by including the 'uspp_spsi = .TRUE.' option in the
> 'pw_export.x' input file, which produces S|psi>, which is orthonormal by
> <psi_i|S|psi_j>. Is this correct? If so, how can I project the two
> different systems on one another (bulk/slab), i.e. which system's
> eigenvector gets the 'S'?
>
> Finally (and sorry for all the questions at once), I've tried using the
> 'uspp_spsi = .TRUE.' option for both the bulk and slab systems, but I
> receive an error message for the bulk (but not the slab!):
>
> *** glibc detected *** pw_export.x: malloc(): memory corruption:
> 0x0000000002b3a650 ***
>
> This occurs right as pw_export.x tries to produce the S|psi> files.
> I'm at a loss, and cannot proceed to troubleshoot this by myself any
> further. Does anyone have any insight into:
> (A) Whether I'm even taking the right approach, or (B) Why I could be
> getting this error for the bulk system but not the slab?
>
>
> Thank you all for your time,
> Hank Seeley
> University of Oregon, Chemistry Dept.
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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