Vibrational coordinates in the electron jump model

The role of quantization of vibrational coordinates in the electron jump model of alkali atom, dimer plus halogen molecule collisions is examined. Despite the bound states of the molecule ions involved, a classical approximation may offer good approximation over a wide collision energy range for the energy distributions of the ions in a single electron jump. Some results are calculated for K + Br₂ and K₂ + Br₂. The theory assumes that the electron jump probability is governed by the electronic matrix element H₁₂ alone. Elementary arguments are offered to suggest that this may be a reasonable approximation.