Classical study of the collision of a highly excited atom with the molecules HF and HCl

The transfer of internal energy and angular momentum in the collision of a highly excited atom with the polar molecules HF and HCl has been examined with use of the classical Monte Carlo approach. The relative motion of the molecule and atomic nucleus is taken to be rectilinear; and the electron-molecule interaction is represented by a cut-off dipole form. Cross sections for transitions involving quantum numbers n, l, and m of the atom, and rotational quantum numbers j and $m_j$ of the molecule have been obtained for a range of collision energies and initial atomic and molecular states. Qualitative agreement is found with some, but not all, features of the experimental measurements. A significant finding of the calculation is the importance of multiple electron-molecule encounters during a single collision.