Multiconfiguration response calculations on the Cameron bands of the CO molecule

Abstract

The spin-forbidden electronic transition a ³Π–X ¹Σ⁺ of the CO molecule constituting the Cameron band system has been studied by multiconfiguration linear and quadratic response methods. A vibrational analysis of the a ³Π and the X ¹Σ⁺ states based on the obtained potential energy and transition mement curves was carried out for emission from the v′= 0, 1 vibronic levels of the a³Π_0,1 spin-sublevels of the upper state to the different lowest v″ vibrational levels of the ground state. The oscillator strength of the 0–0 band is calculated to be 1.35 × 10^–7, which is in agreement with literature values. The Einstein coefficients for the 10 vibronic transitions of the non-rotating molecule have been compared with literature values. The lifetime of the lowest a ³Π₀, J= 0, e level is estimated to be 3.15 s.