Collisional quenching of O(1 D) by rare gas atoms

Abstract

Off-diagonal spin–orbit coupling matrix elements are calculated for the lowest ¹Σ⁺, ³Π and ³Σ^– states of the rare-gas oxides from SCF wave functions in a double-zeta basis. From the resulting parameters and calculated potential energy curves of Dunning and Hay, estimates of the O(¹D) collisional quenching rate constant at 300 K have been made. Calculated values are in good agreement with experiment for Ar and a little too low for Kr and Xe; this may be due to an under-estimation of the spin–orbit parameter. For Ne the calculated value is too low by a factor 10⁴. Reduction of the calculated crossing point by a factor of three would be needed to give agreement with experiment, suggesting that latter may be in error. Experimental data at other temperatures is needed unambiguously to decide the source of error.