[Wien] When to use (or not) onsite hybrid or +U?

[Laurence Marks]

Are there ways to test/calibrate what onsite hybrid or +U to use for metals
(i.e. compounds with states at EF)?

For context, I am doing some test calculations for Mo-Si-B compounds,
currently using PBE without spin. From my analysis of the energies there
are some Mo-B compounds which can be found in the ICSD database, but are
marginal in terms of the heat of formation and are not in published phase
diagrams. Unfortunately the phase diagram work to date has not used the
most modern characterization methods, so it may be incomplete. IMHO if a
structure/composition is in ICSD it should be real.

I know one way to calibrate on-site fractions is matching experimental
atomic positions, but none of these appear to be good enough (there are
fractional occupancies in some cases). Obviously matching band-gaps is
useless, even if I believed in this (which I don't).

Any suggestions?

-- 
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu
"Research is to see what everybody else has seen, and to think what nobody
else has thought" Albert Szent-Györgyi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20210703/5de23fb8/attachment.htm>