Tensor cross sections and collisional depolarization of MgH by He atoms

Abstract

Tensor cross sections for collisions of MgH ( X 2 Σ + ) molecule with helium atom are computed using a new accurate ab initio potential energy surface calculated at the RCCSD (T) level. In the calculations, the MgH bond length is fixed at its experimental value (3.269 bohr). Basis set superposition error is corrected and bond functions are placed at mid-distance between the MgH mass centre and the He atom, for a better description of the van der Waals interaction. The global minimum of the PES is 12.2 cm - 1 . State-to-state tensor and depolarization cross sections are calculated. The tensor cross sections and depolarizing cross sections are computed for kinetic energies up to E c ⩽ 1000 cm - 1 . The tensor cross sections are found to decrease with increasing values of K.