[Wien] Problem with DOS for Fe-Pd system

[Maxim Rakitin]

Dear Prof. Blaha,

Thank you for your review. I'll check the files you mentioned and let 
you know the result.

One thing I'd like to note: I use 24 k-points with inversion, so there 
are only 4 irreducible k-points. Does it mean that my system is 
equivalent to bcc-Fe (1 atom) calculation with 54*24 k-points?

And one question: what should I do to resolve the problem? Do I need to 
increase size of k-mesh only?

Thanks.

Best regards,
    Maxim Rakitin
    South Ural State University,
    Chelyabinsk, Russia
    email: rms85 at physics.susu.ac.ru
    web: http://www.susu.ac.ru

22.04.2010 13:09, Peter Blaha пишет:
> 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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