Dynamic multipole polarizabilities, reduced spectra, and interaction coefficients for N2 and CO

Abstract

Reliable ab initio reduced spectra that serve to calculate dynamic polarizabilities as well as long-range interaction coefficients are presented. The reduced spectra are constructed from perturbed functions that are computed in the single excitation multi-reference averaged coupled pair approach. The static dipole polarizabilities are of the same quality as values obtained in a recent study using elaborated coupled cluster expansions. The dynamic dipole polarizabilities are in excellent agreement with all experimental data available. The higher multipole polarizabilities (l≤3) are also expected to be the most reliable ones up to date. The interaction coefficients for the N2-N2 interaction perfectly match the coefficients obtained from semiempirical anisotropic oscillator strength distributions. For the CO-CO interaction, however, the same quantities differ by up to 10%. We believe our coefficients to be accurate to 3%. © 1999 American Institute of Physics.