Close-coupling calculations of polarized rotational cross sections for (Ar, LiF)

Abstract

Close-coupling calculations with 121 channels at an energy of 155 cm-1 have been made for the rotational scattering of LiF by Ar, using a Lennard-Jones type potential with long range anisotropic terms. Integral cross sections for transitions (jmj )→(j′mj′ ) are given for j = 0, 1, 2, 3, 4 and j′ = 0, 1, 2, 3, 4, 5, and also for the j = 0→8 and j = 0 → 10 transitions. Differential cross sections were obtained for Δj = 1 and j = 0, 1, 2, 3, and for j = 1 →1, 1 →3, 0 →2 and 3 →3 transitions. Rotated scattering amplitudes were used to obtain integral cross sections by numerical integration, but these show little evidence that for Δj ≠ 0 the Δm = 0 transition has a relatively large cross section along an axis perpendicular to the bisector of the angle between the initial and final relative velocity vectors. Certain rules for Δm are suggested, and a comparison with experimental results for (Ar, LiF) and (Ar, CsF) is given.