Irreducible representation of electrons

How To
#1

Dear Q-chem Developers
How to specify the irreducible representation of electrons in Q-Chem to make the SCF calculation converge to a specific state. For example, for a triplet HF molecule using the C2v point group, in PySCF, the electron occupation can be specified through mf.irrep_nelec = {'A1': (4,2), 'B1':(1,1), 'B2':(1,1)} . So in Q-Chem, what keywords need to be used to get the same results?

#2

You can certainly populate specific orbitals (referenced by number, not by irrep) using a $occupied input section.
https://manual.q-chem.com/6.3/sect_occupied.html

Then you will want to use an SCF algorithm that is designed to locate non-Aufbau solutions. Options for that include MOM (or better: IMOM), SGM, and STEP.
https://manual.q-chem.com/6.3/Ch4.S5.SS1.html

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