ROVIBRATIONAL RELAXATION IN COLLISIONS BETWEEN H-2-MOLECULES - I - TRANSITIONS INDUCED BY GROUND-STATE PARA-H-2

We present the results of quantal calculations of cross sections and r ate coefficients for rovibrational transitions in ortho- and para-H-2, induced by collisions with ground state para-H-2. Rovibrational level s up to (v, J) = (3,8) were included in the calculations, and rate coe fficients are available for temperatures 100 less than or equal to T l ess than or equal to 6000 K. Comparison is made with previous calculat ions and with measurements of the rate coefficient for vibrational rel axation v = 1 --> 0. Agreement is found to be good at both high and lo w temperatures, but the measurements exceed the calculations at interm ediate temperatures. Large discrepancies are found with previous calcu lations, which employed a semiclassical method.