EXCITATION OF THE FINE-STRUCTURE TRANSITIONS OF O(3PJ) IN COLLISIONS WITH ORTHO-H2 AND PARA-H2

Ab initio calculations at the SCF and CEPA levels have been performed for the interaction potential between O(3P) and H-2(X 1-SIGMA(g)+) at separations in the van der Waals region. Potential curves for 3-SIGMA-, 3-PI (collinear approach), 3A2, 3B1, 3B2 (orthogonal approach) and 3A' (45-degrees approach) are presented and used in quantum mechanical close coupling calculations of the cross sections for the de-excitation of fine structure transitions in O(3P(J)) by ortho- and para-H-2. The rate coefficients for these and the reverse transitions are evaluated for a wide range of temperatures.