Rotational and vibrational analysis of the CaF B2Σ+–X2Σ+ system

Abstract

A rotation–vibration analysis of the CaFB²S⁺–X²Σ⁺ system is reported. Excitation spectra of CaF are recorded with a cw, 1 MHz bandwidth, dye laser combined with restricted-bandpass (2 Å) fluorescence detection. The accuracy of line measurements is 0.003 cm⁻¹. Nine bands in the Δν = 0 sequence are analyzed (ν″ = 0–2,8,9, 12–15) and selected lines in four Δν = −1 bands (ν″ = 1–4) are used to obtain band origins needed for the vibrational analysis. The main constants (1σ error in parentheses) for the CaF B²Σ⁺ state are: T_e = 18 841.309(3) cm⁻¹. B_e = 0.342604(7) cm⁻¹, ω_e = 572.405(36) cm⁻¹, α_e = 0.002630(6) cm⁻¹, ω_ex_e = 3.143(13) cm⁻¹, R_e = 1.955 Å. The B²Σ⁺ state is found to be in pure precession with A²Π with l = 1.