Abstract
The formalism describing low-energy collisions between a linear molecule and an atom with fine-structure levels is set forth. It is shown that the resulting equations are rendered more tractable by making either the fixed-nucleus or averaged-field approximations. These are usually complementary approximations, but it is shown by physical arguments and numerical calculation that they are in good agreement for Na-N2 collisions. Using the surfaces calculated in an earlier paper, rotational excitation and fine-structure-changing cross sections for Na(2S, 2P)-N2(j) collisions at energies between 0.004 and 0.05 eV are presented, the molecule being in its ground vibrational state. The results are in agreement with the single available measurement.

This publication has 16 references indexed in Scilit: