A Perturbed Rotational State Treatment of Collisions between Polar Molecules

抄録

The low-energy molecule-molecule collisions are studied on the basis of the perturbed rotational state (PRS) functions, which are defined for the system of two polar molecules interacting with each other by the dipole-dipole interaction. By making use of the PRS functions as a basis set, a semiclassical impact-parameter calculation is carried out to determine rotational transition probabilities in HF–HF collisions. It is demonstrated that a near-resonant rotation-to-rotation energy transfer has a large probability and the relevant cross section is determined predominantly by the long-range dipole-dipole force, and that the sum of the quantum numbers m (projections of the rotational angular momenta) of two polar molecules is likely to be conserved.