Absorption studies of Cs2 and Rb2 molecular bands in the visible and near visible

Abstract

By analyzing the temperature dependence of the absorption spectrum of Cs₂ molecules in the visible region of the spectrum we have demonstrated that a group of unusually narrow bands near 7100 Å originate from a very shallow and possibly slightly repulsive part of a ground state potential curve. This may be part of the ³Σ ground‐state potential curve. An analogous set of narrow bands occurs for Rb₂ near 6000 Å. The remaining prominent visible absorption bands for Cs₂ and Rb₂ all originate from molecules near the bottom of the ¹Σ ground state.