[QE-users] ghost like bands ?

[Giuseppe Mattioli]

Dear Kazume

> I think these 'ghost like bands' at 2 eV are irrelevant states
> and should not appear in the band structure.
> Or am I wrong?

Maybe a stupid question. Are they f-like states of Pr, not present as  
valence states in the Pr.pbe-spdn-kjpaw_psl.1.0.0.UPF pseudopotential?
HTH
Giuseppe

Quoting Kazume NISHIDATE <nisidate at iwate-u.ac.jp>:

> Dear all,
>
> I have been checking the SSSP pseudopotentials by applying these to my
> system (Ba2PrBiO6), but I encountered something strange result when I
> calculate its band structure.
>
> I attached the band structure plot along the gamma to X points.
>
> I can obtain the left hand side plot when I use the 'legacy'
> pseudopotentials.
>
>  Ba 137.327 Ba.pbe-spn-kjpaw_psl.1.0.0.UPF
>  Pr 140.90765 Pr.pbe-spdn-kjpaw_psl.1.0.0.UPF
>  Bi 208.9804 Bi.pbe-dn-kjpaw_psl.1.0.0.UPF
>  O 15.999 O.pbe-n-kjpaw_psl.1.0.0.UPF
>
> These are taken from the 'Ready-to-use PP tables'.
> http://pseudopotentials.quantum-espresso.org/legacy_tables
>
> Where the Fermi level was set to zero eV. We can see the two Bi
> states at 2 eV. The same band structure plot can be obtained by using
> the another DFT code (VASP) and I think it is a reliable one.
>
> However, if I switch the Pr pseudopotential to the SSSP one
> (Pr.GGA-PBE-paw-v1.0.UPF) suddenly ghost like states appear at the 2
> eV (right hand side plot).
>
> I know that there are also the SSSP version for Bi and O but these do
> not alter the band structure plot (all these resulted in the left hand
> side plot).
>
> I think these 'ghost like bands' at 2 eV are irrelevant states
> and should not appear in the band structure.
> Or am I wrong?
>
>
> Any information regarding the above points would be greatly
> appreciated.
>
>
>
>
>
>
> 敬具
> Best regards
>
> ---
> 西館数芽
> Kazume NISHIDATE Ph.D
>
> Department of Systems Innovation Engineering,
> Graduate School of Science and Engineering, Iwate University
> 4-3-5 Ueda, Morioka, Iwate, 020-8551 JAPAN
> Phone:+81-19-621-6391
> kazume.nishidate at gmail.com, nisidate at iwate-u.ac.jp
> https://sites.google.com/site/nisidatelab/



GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
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E-mail: <giuseppe.mattioli at ism.cnr.it>