| Abstrakt: |
Vibrational Herzberg bands of the O[sub 2] molecule just below its first O(³P) + O(³P) dissociation limit are since long-known to be perturbed. Jenouvrier et al. [J. Mol. Spectrosc. 198, 136 (1999)] assigned the cause of the perturbations to five vibrational levels supported by the shallow minimum in the 1 ³Π[sub u], potential energy curve around 5.5a[sub 0]. Using ab initio potential energy curves and spin-orbit couplings from previous work [J. Chem. Phys. 116, 1954 (2002)] we present a full quantum calculation of all ungerade rotation-vibration-electronic states of oxygen just below the dissociation threshold, through a total angular momentum quantum number of J = 19. This calculation shows that the original assignment, based on a Hund's case (a) model of a regular 1 ³Π[sub u], multiplet was not correct. Based on our calculation we present a new assignment of the perturbing states: 1 ³Π[sub u,Ω=2](υ=0), 1 ³Π[sub u,1](0), 1 ³Π[sub u,2](1), 1 ³Π[sub u,1](1), and 1 ³Π[sub u,0[sup -]](0) in order of ascending term values. We show the new assignment to be consistent with experimental data and we also propose new spectroscopic parameters for the perturbing states. [ABSTRACT FROM AUTHOR] |
