20.4.3 Specifying orbital configurations

CON, $n_1,n_2,n_3,n_4,\ldots$

Specifies an orbital configuration to be included in the present symmetry. The first CON card must be preceded by a SELECT card. $n_1$, $n_2$ etc. are the occupation numbers of the active orbitals (0,1,or 2). For example, for
OCC,5,2,2;CLOSED,2,1,1;
$n_1$ is the occupation of orbital 3.1 (number.sym), $n_2$ is the occupation of orbital 4.1, $n_3$ of 5.1, $n_4$ of 2.2, and $n_5$ of 2.3 Any number of CON cards may follow each other.

Example for the BH molecule:

OCC,4,1,1;             ! four sigma, one pi orbitals are occupied
CORE,1;                ! first sigma orbital is doubly occupied and frozen
WF,6,1;                ! 6 electrons, singlet Sigma+ state
SELECT                 ! triggers configuration input
CON,2,2                ! 2sigma**2, 3sigma**2
CON,2,1,1              ! 2sigma**2, 3sigma, 4sigma
CON,2,0,2              ! 2sigma**2, 4sigma**2
CON,2,0,0,2            ! 2sigma**2, 1pi_x**2
CON,2,0,0,0,2          ! 2sigma**2, 1pi_y**2