The use of rotationally and orbitally adiabatic basis functions to calculate rotational excitation cross sections for atom-molecule collisions

Four schemes for constructing rotational-orbital basis sets for rotational close coupling calculations for atom-molecule collisions are considered and are applied to calculate 0 → 1, 0 → 2, and 0 → 3 rotational excitation cross sections for He + HF at energies 0.05 and 0.017 eV. Adiabatic basis sets are shown to converge faster than conventional basis sets in all cases; in some cases the difference is very dramatic. Further, l-dominant bases are shown to be useful for the 0 → 2 and 0 → 3 cross sections. (Auth.)