[Wien] About the magnetic moment of vanadium in vanadium sulphide

[Fecher, Gerhard]

Did you read and understand
   Rationale for mixing exact exchange with density functional approximations
   John P. Perdew, Matthias Ernzerhof, and Kieron Burke
   The Journal of Chemical Physics 105 , 9982 (1996)
or similar articles and references there ?

Usually, the parameters of the functionals (including hybrids) are well justified and not arbitrary numbers (even for the empirical functionals as B3LYP)
In my opinion it is bad habit to change functionals in an arbitrary way.
Indeed, one may in the same way change the parameters of the PBE-GGA (or any other LDA or GGA functional) until a calculation fits some property of some haphazardly selected material,
but what do we learn from such a procedure other than nonsense ?


Ciao
Gerhard

DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
"I think the problem, to be quite honest with you,
is that you have never actually known what the question is."

====================================
Dr. Gerhard H. Fecher
Institut of Inorganic and Analytical Chemistry
Johannes Gutenberg - University
55099 Mainz
and
Max Planck Institute for Chemical Physics of Solids
01187 Dresden
________________________________________
Von: Wien [wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von Abderrahmane Reggad [jazairdz at gmail.com]
Gesendet: Dienstag, 12. September 2017 16:57
An: wien at zeus.theochem.tuwien.ac.at
Betreff: Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Martin

I still confused and not convinced with my results.

It's not the band gap of NiS to take as the only criterion for the choice of the amount of excact exchange, but also the experimental values of magnetic moment. This amount allows me to get magnetic moment values close to the experimental values for many 3d transition metal sulphides like NiS, CrS, FeS and CoS.

For the use of EECE method for NiS semiconductor ; this later is not a sp semiconductor but  a splitting d bands semiconductor.


Best regards