Infrared absorption line strengths of the Na center dot center dot center dot FH van der Waals molecule

The dipole moment function of the Na FH van der Waals molecule obtained in accurate multireference configuration interaction calculations and the rece ntly published ab initio potential energy surface for NaFH [Topaler et al., J. Chem. Phys. 108, 5349 (1998)] have been used to predict the infrared ab sorption line strengths of Na...FH for several fundamental and overtone tra nsitions. The fundamental excitation of the HF stretch mode in Na...FH is e nhanced by a factor of 2.2 compared to the isolated HF molecule, and the fi rst and second overtones are enhanced by factors of 21 and 53, respectively . (C) 1999 American Institute of Physics. [S0021-9606(99)00910-1].