A HARMONIC POTENTIAL FUNCTION FOR LITHIUM SODIUM DIFLUORIDE, LINAF2

A harmonic force field for the mixed alkali halide dimer LiNaF2 is rep orted based on microwave centrifugal distortion coefficients and matri x-isolation vibrational frequencies for both (LiNaF2)-Li-6 and (LiNaF2 )-Li-7, and an ab initio force field. it is compared to RHF and MP2 ab initio calculations, with a particular emphasis on determining reliab le general alkali halide mean amplitudes of vibration l. Detailed comp arisons between ionic model, RHF, MP2, and CCSD ab initio dipole momen t values and the experimental value of 2.64(2) D are also made. (C) 19 97 Elsevier Science B.V.