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

[pieper]

Be aware that Hund's rules do rest on certain assumptions about the 
relative strength of intra- and inter-atomic couplings. There are, after 
all, a lot of para- or diamagnetic materials around. Try to look that 
up. Is your Vanadium sulphide magnetically ordered from experiment?

In your case the 0.05 mu_B is probably an instance of the problems 
frequently encountered in strongly correlated systems: There are several 
states with very similar total energy, but with very different 
configurations of charges and spins. Search the mailing list for 
magnetic ordered states, or for orbital order.

The scf cycle of DFT will tend to stay near the configuration it started 
from. If you start from a standard non-magnetic configuration set by 
lstart it won't look at magnetically ordered states. Try to start the 
scf cycle from magnetic configurations - you can set them up in lstart - 
and compare the total energies. Be carefull to change only the magnetic 
starting configuration, NOT RMT's, RKMAX, K-mesh, crystal symmetry, 
whatever.

Note that the starting spin configurations you can set in lstart may 
well be not good enough. You may have to modify the density matrix of 
the problematic orbitals by hand and let the scf cycle dig itself in in 
that state by using the option -orbc. This also has been explained in 
posts in this mailing list before - perhaps most detailed by prof. Tran.

Good luck with your calculations

---
Dr. Martin Pieper
Karl-Franzens University
Institute of Physics
Universitätsplatz 5
A-8010 Graz
Austria
Tel.: +43-(0)316-380-8564


Am 02.09.2017 12:24, schrieb Abderrahmane Reggad:
> Dear wien2k users
> 
> I have calculated the magnetic moment of  vanadium sulphide in NiAs
> structure using the EECE méthod with alpha parameter equals to 0.05.
> 
> despite the fact that the number of inpariated electrons is equal to 3
> I found that the magnetic moment of vanadium is equal to 0.05 MB which
> is inconsistent with the prediction of Hund.
> 
> Best regards
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