Analysis of the 118.6 μm laser magnetic resonance spectra of PH, X³Σ⁻ and a¹Δ

Measurement and analysis of the 118.6 μm far infrared laser magnetic resonance spectra of the PH radical in its X 3 Σ − and a 1 Δ states are reported. The following rotational and fine structure parameters have been determined: X 3 Σ − : B 0 = 8.412018 (27) cm −1 , λ 0 = 2.2067 (15) cm −1 , γ 0 = −0.076476 (48) cm −1 ; a 1 Δ: B 0 = 8.4392925 (46) cm −1 . The derived hyperfine constants are: [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]; a 1 Δ: a H = 28 (15) MHz, a P = 768 (37) MHz. Within experimental error the hyperfine parameters yield identical values of [Formula: see text] for both electronic states.