The user documentation for Hibridon
BASISTYPE = 14
System subroutine: sy2del
Basis subroutine: hiba14_2del.F90
Ref. B. Nizamov, P. J. Dagdigian, Y.-R. Tzeng, and M. H. Alexander, J. Chem. Phys. 115, 800 (2001).
NTERM: (the number of potential surfaces involved: this should be 2 in this case). This parameter can not be changed
NPAR: number of lambda-doublet components included
NPAR = 1, just ε = +1 states are includedNPAR ≠ 1, both ε = +1 and ε = -1 states are includedJMAX: maximum molecular rotational level included in channel basis
IGU: inversion symmetry of states included in expansion
IGU = +1 for gerade states (for heteronuclear molecules IGUshould be +1)IGU = -1 for ungerade statesISA: nuclear permutation symmetry (s/a label) of states included in the expansion
If the flag IHOMO is .TRUE., then only s states will be included if ISA = +1 and only a states if ISA = -1BROT: rotational constant