CLASSICAL DYNAMICS OF THE O(3P)+CS(X1-SIGMA+)-]CO(X1-SIGMA+)+S(3P) REACTION ON THE GROUND TRIPLET POTENTIAL-ENERGY SURFACE

The dynamics of the O(3P) + CS (X1Σ+) → CO (X1Σ+) + S(3P) reaction at relative collision energies not far from the threshold energy (0.01-0.5 eV) has been studied by means of the quasiclassical trajectory method, using a reasonable Sorbie-Murrell potential energy surface derived from MNDO/CI calculations and spectroscopic data. An inverted vibrational distribution of the CO molecules was found in very good agreement with the experimental distributions, supporting the laser action of this reaction. A significant hot nonthermal rotational distribution was also obtained, but there are no experimental data to be compared with. The calculated rate coefficient at room temperature is one order of magnitude lower than the experimental one, even though a slightly better accord would be expected if a hotter vibrational distribution of CS reactant molecules were used, because in bulk experiments at room temperature, a fraction of these molecules could be in higher vibrational levels (1775 K) due to the reaction of O(3P) atoms with undissociated CS2(X 1Σg +) molecules. © 1990.