Classification of the electrons in the two fermion irrep

[Mhmd Al ahmad]

Dear Dirac experts
I'm trying to run a calculation for an open-shell molecular system consisting of three atoms (X-Y-X) with a negative charge. On the DIRAC website, we can read "For symmetry groups with inversion symmetry, you need to specify the distribution of the electrons in the two ?fermion irreps ". Practically, how can we classify electrons in the two fermion irreps
With my best regards,
mohamed.

[Peterson, Kirk]

Dear Mohamed,

 

this just means to specify the occupations in terms of gerade and ungerade spinors.

 

regards,

 

-Kirk

 

From: <dirac...@googlegroups.com> on behalf of Mhmd Al ahmad <alahm...@gmail.com>
Reply-To: "dirac...@googlegroups.com" <dirac...@googlegroups.com>
Date: Monday, May 22, 2023 at 7:01 AM
To: dirac-users <dirac...@googlegroups.com>
Subject: [dirac-users] Classification of the electrons in the two fermion irrep

 

[EXTERNAL EMAIL]

--
You received this message because you are subscribed to the Google Groups "dirac-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to dirac-users...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/dirac-users/3a6efad7-1a80-4fa5-9765-bb8d5884552fn%40googlegroups.com.

[Trond SAUE]

On 5/22/23 16:00, Mhmd Al ahmad wrote:

I'm trying to run a calculation for an open-shell molecular system consisting of three atoms (X-Y-X) with a negative charge. On the DIRAC website, we can read "For symmetry groups with inversion symmetry, you need to specify the distribution of the electrons in the two ?fermion irreps ". Practically, how can we classify electrons in the two fermion irreps

You have to distinguish gerade and ungerade.

All the best,

  Trond

--

Trond Saue
Laboratoire de Chimie et Physique Quantiques
UMR 5626 CNRS --- Université Toulouse III-Paul Sabatier
118 route de Narbonne, F-31062 Toulouse, France

Phone : +33/561556361 Fax: +33/561556065
Mail : trond...@irsamc.ups-tlse.fr
Web : https://dirac.ups-tlse.fr/saue
DIRAC : http://www.diracprogram.org/
ESQC : http://www.esqc.org/
ERC Advanced Grant: HAMP-vQED

Book: Principles and Practices of Molecular Properties: Theory, Modeling, and Simulations

[Ilias Miroslav, doc. RNDr., PhD.]

Hi,

you may try https://www.diracprogram.org/doc/master/manual/wave_function/scf.html#autocc first.

Miro

---

From: dirac...@googlegroups.com <dirac...@googlegroups.com> on behalf of Mhmd Al ahmad <alahm...@gmail.com>
Sent: Monday, May 22, 2023 16:00
To: dirac-users <dirac...@googlegroups.com>
Subject: [dirac-users] Classification of the electrons in the two fermion irrep

 

--