R. Hernandez-lamoneda et A. Ramirez-solis, Spin-orbit coupling in highly vibrationally excited O-2(upsilon) and O-2(upsilon=0)-O-2(upsilon), CHEM P LETT, 321(3-4), 2000, pp. 191-196
Highly correlated ab initio calculations of the ground and low-lying electr
onic states of O-2 and O-4 together with a semi-empirical estimate of the s
pin-orbit coupling among them have been performed. For the diatomic, our ca
lculations agree well with recent spectroscopic measurements. For the O-2(v
= 0)-O-2(v) collision system, avoided crossings allow mixing of the electr
onic configurations with appreciable spin-orbit coupling into the lowest-ly
ing excited states. As a consequence, spin-orbit transitions can occur at s
ignificantly lower vibrational energies of the O-2(v) moiety induced by col
lisions with O-2(v = 0). This mechanism must be partially responsible for t
he observed jump in depletion rates of O-2(v) determined experimentally, (C
) 2000 Elsevier Science B.V. All rights reserved.