Investigations of pure rotational transitions of H-2 perturbed by He. II. High-temperature calculations and extrapolations

Close-coupling calculations of broadening and shifting coefficients of Rama n S-0(j) lines of H-2 perturbed by He are performed up to 3000 K. They are used to test two approximate methods, the quantum coupled states theory and the RB semiclassical model. They are further applied to study the use of s imple functional forms for fitting and extrapolating experimental data, and some new fits of experimental broadening coefficients are given. (C) 2001 American Institute of Physics.