AB-INITIO CALCULATION OF THE NUCLEAR-QUADRUPOLE COUPLING-CONSTANTS OFROVIBRATIONAL LEVELS IN THE X(2)SIGMA(-() STATE OF ALL ISOTOPIC VARIANTS OF LIH)

The Li-7, Li-6 and H-2 quadrupole coupling constants of rovibrational levels of (LiH-)-Li-7-H-1, (LiH-)-Li-6-H-2, (LiH)-Li-7-H-2- and (LiH-) -Li-6-H-2 in their ground electronic state are calculated from molecul ar wave functions which explicitly describe nuclear displacements. The strength of the Li-7 coupling is predicted to be more than an order o f magnitude larger than that of the H-2 and Li-6 coupling. The vibrati onal dependence of the nuclear quadrupole coupling constants is found to be quite significant for all the isotopomers. The qualitative featu res of the Li-7, Li-6 and H-2 coupling in these species are consistent with those reported for LiH ((1) Sigma(+)) and LiH+ ((2) Sigma(+)).