21.3.1 Selecting configurations

SELECT,ref1,ref2,refthr,refstat,mxshrf;

This card is used to specify a reference configuration set other than a CAS, which is the default. Configurations can be defined using CON cards, which must appear after the SELECT card. Alternatively, if ref1 is an existing MOLPRO record name, the configurations are read in from that record and may be selected according to a given threshold.

The select card should normally be placed directly after the WF or REF card(s), or, if present, the RESTRICT cards. The general order of these cards is

WF (or REF)
RESTRICT (optional)
SELECT (optional)
CON (optional)

ref1=rec1.file:

(rec1$>$2000) The configurations are read in from the specified record. If ref1 is not specified, the program assumes that the configurations are read from subsequent CON cards (see CON).

ref2=rec2.file:

(rec2$>$2000) additional configurations are read from the specified record. If rec2 is negative, all records between rec1 and abs(rec2) are read. All configurations found in this way are merged.

refthr:

Selection threshold for configurations read from disc (records rec1-rec2). This applies to the norm of all CSFs for each orbital configuration.

refstat:

Specifies from which state vector the configurations are selected. This only applies to the case that the configurations were saved in a state-averaged calculation. If refstat is zero or not specified, the configurations are selected from all states. If refstat is greater than zero, then the specified reference state is used. If refstat is less than zero, then all appropriate reference states are used. Lastly, if refstat is of the form istat1.istat2, states istat1 through istat2 are used.

mxshrf:

maximum number of open shells in the selected or generated configurations.