Transition moments for the B 3Σ−u–X 3Σ−g and 3Πu–X 3Σ−g transitions in O2

Abstract

Multiconfiguration self‐consistent field wavefunctions are used to calculate the transition moments for the two lowest dipole allowed transitions in O₂. The transition matrix element for the B–X transition calculated at R_e of the ground state corresponds to an oscillator strength of 0.18, in good agreement with the experimental integrated oscillator strength 0.16 of the Schumann–Runge continuum. The B–X transition moment is calculated as a function of internuclear separation. The transition matrix element to the repulsive valence ³Π_u state calculated at R_e of the ground state corresponds to an oscillator strength of 0.003. Although the weak ³Π_u absorption continuum is masked by the strong Schumann–Runge continuum below 1750 Å, this ³Π_u absorption may contribute to the background continuum in the Schumann–Runge band region at low temperature.