Collision-theory calculations for some quadrupole-quadrupole reactions of O( 1D)

Abstract

Langevin-type capture rate constants have been obtained for collisions of O( 1D) with CO 2, H 2, N 2 and O 2, using approximate quasiclassical trajectory calculations with a combined quadrupole-quadrupole + London + Morse potential, over the temperature range 10–600 K. The calculated capture rates depend about equally on the quadrupole-quadrupole and London potentials and are independent of the Morse potential. Rate constants are obtained in good agreement with listed experimental values at 300 K when the calculated capture rates are multiplied by a factor of 0.2 for electronic degeneracy and by a factor of 1.0, 0.545 or 0.455 for orientation. These orientation factors derive from the angular factors of the quadrupole-quadrupole potential. For the reactions with O 2 and CO 2 the orientation factor is 1.0 (no preferred orientation), for reaction with H 2 it is 0.545 (end-on collisions favoured), and for reaction with N 2 it is 0.455 (perpendicular collisions favoured).