**WAVE FUNCTIONS  

Purpose:

Specification of which calculation to perform and optionally of the number of symmetries for consistency check of input.

.BASIS SET  

Default: specified by integral program
SPMquotREAD (LUINP,*) (NBAS(I), I = 1,NSYM)"
Number of basis functions per symmetry.

.CI  

Configuration interaction calculation.  

.FLAGS  

SPMquotREAD (LUINP,NMLSIR)"
Read namelist SPMquotNMLSIR ... END"
Only for debugging. Set internal control flags directly. Usage is not documented.

.HF  

Closed shell or one open shell restricted Hartree-Fock     calculation.

.INTERFACE  

Write the "SIRIFC" interface file  for post-programs.

.MCSCF  

MCSCF calculation. 

.MP2  

Møller-Plesset second order perturbation theory   calculation.

.NSYM  

Default: specified by integral program
SPMquotREAD (LUINP,*) NSYM"
Number of spatial Abelian symmetries (1, 2, 4, or 8), corresponding to or one of its subgroups.

.PRINT  

SPMquotREAD (LUINP,*) IPRSIR"
General SIRIUS print level and default for all other print parameters.

.RESTART  

restart SIRIUS , the SIRIUS restart file ("f21" file) must be available

.SCF  

Alias for the ".HF  " keyword.

.STOP  

READ (LUINP,'(A20)') REWORD
Terminate SIRIUS according to the instruction given on the following line. Three stop points are defined:

1. " AFTER INPUT"
2. " AFTER MO-ORTHONORMALIZATION"
3. " AFTER GRADIENT"

.TITLE  

SPMquotREAD (LUINP,'(A)') TITLE(NTIT)"
Any number of title lines (until next line beginning with "." or "*" prompt). Up to 6 title lines will be saved and used in output, additional lines will be discarded.

.WESTA  

Write the "SIRIFC" interface file for WESTA post-program

.BASIS SET  

Default: specified by integral program
SPMquotREAD (LUINP,*) (NBAS(I), I = 1,NSYM)"
Number of basis functions per symmetry.

Comments:

ABACUS: If the full molecular Hessian is calculated in ABACUS and the number of symmetries (NSYM) is greater than one, then the MCSCF wave function will automatically be calculated in determinants  and, if singlet, ".PLUS COMBINATIONS"). This is so because the CSFs can only have one spatial symmetry, and it is generally necessary to solve linear response equations of several symmetries to get the full molecular Hessian.

BASIS SET is provided such that the number of basis functions in each symmetry may be specified if SIRIUS is modified to interface to an integral program which doesn't write this information to the integral file.