Observation and characterization of a doubly excited electronic state of 39K 2

Abstract

Supersonic nozzle beam and optical-optical double resonance techniques using a cw single-mode ring dye laser as a pump and a narrow-band pulsed dye laser as a probe have been used to make the first spectroscopic study of a doubly excited electronic state ( 1Σ g −) of 39K 2 above the (lowest) 2Σ g + state of K 2 +. Molecular constants (in cm −1) are T e = 36599.7(1), ω e = 43.47(3), ω eχ e = 0.225 (3), B e = 0.0444(3), α e = 0.00027 (5), and R e = 4.41 Å.