*CONFIGURATION INPUT  

Purpose:

To specify the configuration part in MCSCF and CI calculations.

.SPIN MULTIPLICITY  

Required for MCSCF and CI wave functions   .
READ (LUINP,*) ISPIN
For CSF basis: state spin multiplicity  = 2S + 1, where S is the spin quantum number.
For determinant basis this option determines the minimum spin multiplicity. The value is determined as (ISPIN-1)/2.

.SYMMETRY  

Required for MCSCF and CI wave functions.
READ (LUINP,*) LSYM
Spatial symmetry  of MCSCF wave function

.INACTIVE ORBITALS  

Required.
READ (LUINP,*) (NISH(I),I=1,NSYM)
Number of inactive orbitals  each symmetry.

.ELECTRONS (active)  

Required.
READ (LUINP,*) NACTEL
Number of active electrons  (the number of electrons to be distributed in the active orbitals). The total number of electrons is this number plus two times the total number of inactive orbitals.

.CAS SPACE  

READ (LUINP,*) (NASH(I),I=1,NSYM)
CAS calculation: Active orbitals  each symmetry.

.RAS1 SPACE  

READ (LUINP,*) (NAS1(I),I=1,NSYM)
RAS calculation: RAS1 orbital space 

.RAS2 SPACE  

READ (LUINP,*) (NAS2(I),I=1,NSYM)
RAS calculation: RAS2 orbital space 

.RAS3 SPACE  

READ (LUINP,*) (NAS3(I),I=1,NSYM)
RAS calculation: RAS3 orbital space 

.RAS1 HOLES  

READ (LUINP,*) NHL1MN,NHL1MX
Minimum and maximum number of holes  in RAS1; alternative to ".RAS1 ELECTRONS  "

.RAS1 ELECTRONS  

READ (LUINP,*) NEL1MN,NEL1MX
Minimum and maximum number of RAS1 electrons; this can alternatively be specified with ".RAS1 HOLES  "

.RAS3 ELECTRONS  

READ (LUINP,*) NEL3MN, NEL3MX
Minimum and maximum number of RAS3 electrons

Comments:

SYMMETRY Specifies total spatial symmetry of the wave function in symmetry and its subgroups: , , , , , , . The symmetry number of wave function follows MOLEULE output ordering of symmetries ( subgroup IR's).

CAS and RAS    are exclusive and both cannot be specified in the same MCSCF or CI    calculation, one of them must be specified.