Investigations of metal ion – rare gas pairs by optical spectroscopy: High resolution analysis of the A2Πr–X2Σ+ system of BeAr+

Abstract

Rotational analyses have been performed for the 1–0, 0–0, 0–1, 0–2, 0–3, and 0–4 bands of the A²Π_r–X²Σ⁺ system of BeAr⁺ near 4000 Å. Molecular constants have been obtained by direct least squares fits of the line frequencies to model Hamiltonians. The Λ-type doubling in the A state is compared with that found for other nine valence-electron systems. RKR curves are calculated for both states, and provide an estimate of D_c″ = 4100 ± 200 cm⁻¹ for the X²Σ⁺ state. Franck–Condon factors and r-centroids for the transition are also reported.