NVMINS: lowest vibrational level for sigma state

NVMAXS: higest vibrational level for sigma state

NVMINP: lowest vibrational level for pi state

NVMAXP: higest vibrational level for pi state

JMIN: the minimum rotational angular momenta for each ² channel

JMAX: the maximum rotational angular momenta for each ² channel

in each spin-orbit manifold with convention omega .le. j .le. jmax+0.5

NMIN: the minimum Hund's case (b) rotational angular momenta for the ² state

NMAX: the maximum Hund's case (b) rotational angular momenta for the ² state

JMIN, JMAX, NMIN, NMAX are defined separately for each vibrational level

IPERT: Each vibrational Pi level ivp may be perturbed by one sigma vibrational level IVS. This level is given by ivs=ipert(ivp) (see hisysgpi)

IGUPI: permutation inversion symmetry of ² electronic state

IGU = 1 for gerade states
IGU = -1 for ungerade states

IGU = 1 for gerade states
IGU = -1 for ungerade states

for heteronuclear molecules both IGUPI and IGUSG should be +1

NPARPI: number of ² symmetry doublets included

NPAR = 2 will ensure both lambda doublets
NPARPI = 1 just = 1 doublets;
NPARPI = -1, just = -1 doublets

ISYMSG: if ISYM =+1, then the electronic symmetry of the ² state is sigma-plus if ISYM = -1, then the electronic symmetry is sigma-minus ISA: s/a symmetry index, if the molecule is homonuclear (ihomo=t) then, if isa=+1 then only the s-levels (both for sigma and pi) are included in the basis, if isa=-1, then only the a-levels are included

ISG: if isg=1 and ipi=0 then 2sig + atom scattering

IPI: if ipi=1 and isg=0 then ² + atom scattering

if isg=1 and ipi=1 then ²-2sig + atom scattering