MULTIQUANTUM VIBRATIONAL TRANSITIONS IN O-2(NU-GREATER-THAN-OR-EQUAL-TO-25)-2(NU=0) COLLISIONS(O)

The quenching of highly vibrationally excited O-2 in collision with O- 2(v = 0) is investigated using a semiclassical wave packet method. We find that nonreactive collisions dominate the relaxation of O-2(v) and for v in the range 25 to 30 the reactive channel makes little contrib ution to the quenching process, in agreement with our earlier investig ation. We report vibrational transition cross sections and relaxation rate coefficients for v = 25 to 30 of the excited O-2(v) molecule. Our study shows that a multiquantum process involving a 2 --> 1 vibration al transition which has not been included in previous calculations mak es an important contribution to the rate coefficients for the relaxati on of O-2 vibrational levels v greater than or equal to 27. (C) 1998 E lsevier Science B.V. All rights reserved.