Degeneracy breakdown

Concerns issues with computing quasiparticle corrections to the DFT eigenvalues - i.e., the self-energy within the GW approximation (-g n), or considering the Hartree-Fock exchange only (-x)

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javad
Posts: 44
Joined: Fri Feb 28, 2014 10:23 pm

Degeneracy breakdown

Post by javad » Thu Feb 06, 2020 10:33 am

Dear

I have a moleculer system with different levels that are close in energy,
when I run GW calculations I get this message

[WARNING]Detected a degeneracy breakdown induced by COHSEX Sc of 41.75898% in states (n,k)=(448,1)-(443,1)

is this important? or not?

best
javad
Javad Exirifard
IPM - Institute for Research in Fundamental Sciences
P. O. Box 19395-5746
Niavaran Square
Tehran, Iran

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claudio
Posts: 526
Joined: Tue Mar 31, 2009 11:33 pm
Location: Marseille
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Re: Degeneracy breakdown

Post by claudio » Thu Feb 06, 2020 3:29 pm

Dear Javad

it can happen that in some systems there are accidental degeneracies,
so in this case this is not a problem.

You should check if the degeneracy that is broken was due to some symmetry
or accidental.

best
claudio
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

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