Band Spectra and Energy of Dissociation of the Rubidium Molecule

Measurements and vibrational analysis of the violet and blue band systems of Rb₂ have been made in absorption. Quantum numbers have been assigned to 118 and 160 bands in the two systems, respectively. The upper vibrational frequency of the violet system is 40.42 cm^-1 and that of the blue one, 36.46 cm^-1. The lower level, common to the two systems, is ¹Σ ground state, and its vibrational frequency is found to be 57.45 cm^-1. The energies of dissociation of the three states of the molecule have been determined by means of extrapolation, and the value for the ground state is 0.49 ±{} 0.02 volt. A green edge of the blue system at 5032A has been observed.