The BaI X2Σ+ and B2Σ+ Electronic States Through B2Σ+–X2Σ+ and C2Π–X2Σ+ Band Systems Analysis

Abstract The near-infrared spectrum of the B 2 Σ + – X 2 Σ + band system of the BaI molecule, obtained from the chemiluminescent reaction Ba + I 2 and also by laser-induced fluorescence (LIF), was recorded by using Fourier transform spectroscopy (FTS). The LIF spectra were obtained by using a Ti:sapphire single-mode laser excitation. Resolved rotational data, originating from 32 vibrational levels (0 ≤ v ≤ 31) in the X 2 Σ + state and from 24 vibrational levels (0 ≤ v ≤ 19, and v = 21, 22, 23, 26) in the B 2 Σ + state, were used in the final analysis. Previously recorded data for the C 2 Π– X 2 Σ + band system (with Δ v = 0), taken from C. A. Leach, A. A. Tsekouras, and R. N. Zare, J. Mol. Spectrosc. 153, 59–72 (1992), were added to the present work data field. Accurate and improved molecular constants for the X 2 Σ + , B 2 Σ + , and C 2 Π states were derived from a simultaneous treatment of the whole data set.