Emission Spectrum of the PO Molecule. Part IV. Spectrum in the Region 7000–12 000 Å

Abstract

A new transition, A2Σ+–B2Σ+, of the PO molecule has been observed in the region 7000–12 000 Å. From the rotational analysis of the bands numerous perturbations have been observed in the ν = 0–5 levels of the A2Σ+ state. These perturbations have been shown successfully to be partly due to the B′2Π1 state and partly due to a new 4Σ− state. A shift has been detected in the A2Σ+, ν = 3, 4, and 5 levels, which has been attributed to a vibrational perturbation produced by the F2Σ+ state. A new G2Σ+–A2Σ+ transition also is reported.