[Wien] Problem with DOS for Fe-Pd system

[Peter Blaha]

I checked the qtl file you sent.

You do not have any "band-dispersion", i.e. all 4 k-points in the file have
identical energies. E.g.:

...
  BAND: 236
    0.48370  1 0.03555    0.00938 0.00117 0.02500 0.00000 0.02500 0.00000
  ...
    0.48370 54 0.00586    0.00349 0.00000 0.00237 0.00000 0.00237 0.00000
    0.48370 55 0.49372
    0.48370  1 0.03555    0.00938 0.00117 0.02500 0.00000 0.02500 0.00000
    0.48370  2 0.00891    0.00049 0.00021 0.00820 0.00448 0.00372 0.00000
  ...
    0.48370 54 0.01267    0.00048 0.00028 0.01191 0.00244 0.00947 0.00000
    0.48370 55 0.49372
    0.48370  1 0.03555    0.00938 0.00117 0.02500 0.00000 0.02500 0.00000
    0.48370  2 0.00892    0.00049 0.00021 0.00821 0.00448 0.00373 0.00000
  ...
    0.48370 54 0.01267    0.00048 0.00028 0.01191 0.00244 0.00947 0.00000
    0.48370 55 0.49372
    0.48370  1 0.03555    0.00938 0.00117 0.02500 0.00000 0.02500 0.00000
    0.48370  2 0.00892    0.00049 0.00021 0.00821 0.00448 0.00373 0.00000
  ...

When all k-pints have identical energies, the DOS consists of "delta-peaks" at
those energies and since your DOS energy-mesh usually does not coincide with any of those
eigenvalues, you find only zero DOS. (You can see in case.outputt that the integrated DOS
properly increases whenever an eigenvalue was covered).

Check case.output1up*. Are the eigenvalues the same ? Do they agree with the
eigenvalues listed in case.qtlup ? Do the k-points agree with case.klist ?
Check case.klist: do you have 4 times the same k-point ?

In any case. the DOS will be crude. You are using a 3x3x3 supercell, but probably have
only a 2x2x2 k-mesh. This is equivalent to a bcc-Fe calculation with only 6x6x6 k-points,
which is certainly not sufficient.

PS: Next WIEW2k release will have an option to get a DOS with just ONE k-point using
a broadening scheme. But be aware of the fact, that this DOS could be "lousy" unless
you have really large cells and depends a lot on the broadening parameters.

Maxim Rakitin schrieb:
> Dear WIEN2k users,
> 
> I have a problem with DOS for Fe-Pd system. Namely, I got null values 
> for all tot, s, p, d, d-eg, d-t2g, f orbitals, and it seems very strange 
> for me. Calculations of pure Fe gave me correct DOS states. Moreover, I 
> got reasonable results of DOS for Fe-H-Pd system.
> 
> I performed spin-polarized calculation of Fe53Pd bcc system (see 
> attached Fe53Pd.struct file (after minimization)). I used GGA-PBE96 XC 
> potential., RKmax=8.75, size of k-mesh was 24 (4 irreducible k-points). 
> SCF cycle was started by the following command: *min -j "runsp_lapw -p 
> -I -ec 0.0001 -cc 0.001 -fc 1.0 -i 200"*, after it minimization 
> completed successfully. Then I ran the following commands to generate 
> *.qtl* files: *x lapw2 -p -c -qtl -up* and *x lapw2 -p -c -qtl -dn*, 
> created Fe53Pd.int file (see in attachment) and ran *x tetra -c 
> -up/-dn*. After it I got Fe53Pd.dosXup/dn files with 0.00000000 values 
> for all states. I don't know where the problem came from, maybe I don't 
> have proper *.vector* files in $SCRATCH directory. I've already tried to 
> rerun *x lapw1 -p -c -up/-dn* and then *x lapw2 -p -c -qtl -up/-dn*, but 
> the result was the same.
> 
> Could anyone suggest me what to do to get correct DOS? Do I need to 
> provide any other input/output file? Any help will be really 
> appreciated. Thanks in advance.
> *_
> Environment:_*
> *WIEN2k version:* WIEN2k_08.3 (Release 18/9/2008)
> *Machine type:* cluster with Infiniband interconnect and Torque batch system
> *OS type:* Linux version 2.6.16.54-0.2.5-smp (geeko at buildhost) (gcc 
> version 4.1.2 20070115 (prerelease) (SUSE Linux)) #1 SMP Mon Jan 21 
> 13:29:51 UTC 2008
> *Fortran compiler:* 10.1.015
> *MKL libraries:* 10.0.3.020 (em64t)
> 
> -- 
> Best regards,
>    Maxim Rakitin
>    South Ural State University,
>    Chelyabinsk, Russia
>    email: rms85 at physics.susu.ac.ru
>    web: http://www.susu.ac.ru
> 
> 
> ------------------------------------------------------------------------
> 
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-- 
-----------------------------------------
Peter Blaha
Inst. Materials Chemistry, TU Vienna
Getreidemarkt 9, A-1060 Vienna, Austria
Tel: +43-1-5880115671
Fax: +43-1-5880115698
email: pblaha at theochem.tuwien.ac.at
-----------------------------------------