Effective potential energies and transport cross sections for atom-molecule interactions of nitrogen and oxygen

The potential energy surfaces for H-2-N and N-2-N interactions are calculated by accurate ab initio methods and applied to determine transport data. The results confirm that an effective potential energy for accurately deter-mining transport properties can be calculated using a single predetermined orientation. A simple method is developed to determine the dispersion coefficients of effective potential energies. Effective potential energies required for O-2-O collisions are determined. The H-2-N, N-2-N, O-2-H. and O-2-O collision integrals are calculated and tabulated for a broad range of temperatures. The theoretical values of the N-2-N and O-2-O diffusion coefficients compare well with measured data available at room temperature.