Keyword category:

Configuration Interaction / Spin State

SINGLET

Description

Constrains the spin multiplicity of the primary CI eigenstate to be 1, i.e., a singlet, corresponding to no unpaired electrons. For ROOT=n, the nth lowest-energy singlet CI eigenstate will be the primary eigenstate.

See also:

DOUBLET, TRIPLET, C.I., ROOT=n, openn,m