- $closed shells
Specification of MO occupation for RHF, e.g.
a1g 1-4 ( 2 )
a2g 1 ( 2 )
- $open shells type=1
MO occupation of open shells and number of open shells.
type=1 here means that there is only a single open shell
consisting e.g. of two MOs:
b2g 1 ( 1 )
b3g 1 ( 1 )
a = 1 b = 2
Roothaan parameters for the open
shell, here a triplet case. define recognizes most cases and
suggests good Roothaan parameters.
For further information on ROHF calculations, see the sample input
in Section 19.6 and the tables of Roothaan parameters in