The band spectrum of barium oxide

Abstract

New measurements of the bands of barium oxide have been made from moderate-dispersion and high-dispersion spectrograms. The band-head data of the early investigations have been extended in the red region as far as λ 8000. The bands lying between λ 8000-λ 4300 have been assigned to a single system. The equation representing the wave-numbers of band-heads is ν = 16815.89 + {495.36 (ν' + ½) - 1.12 (ν' + ½)2} - {671.48 (ν'' + ½) - 2.20 (ν'' + ½)2}. The bands (0, 3), (0, 2), (1, 2), (1, 1) and (2, 1) have been analysed. Their rotational structure reveals that the band system is due to a 1Σ → 1Σ transition. The following rotational constants have been evaluated: Be' = 0.30995 cm.-1 Be'' = 0.36440 cm.-1 α' = 0.0011 α'' = 0.0016 De' = - 0.483 × 10-6 De'' = - 0.430 × 10-6 β' = 0.24 × 10-9 β'' = - 1.2 × 10-9 re' = 1.938 × 10-8 cm. re'' = 1.787 × 10-8 cm. Ie' = 89.44 × 10-40 gm. cm.2 Ie'' = 76.04 × 10-40 gm. cm.2