New observations and analysis of the infrared vibration–rotation spectrum of H3+

Abstract

The coverage of the infrared spectrum of the [Formula: see text] molecular ion is extended by further measurements of the emission from a small high-pressure hollow-cathode electrical discharge cell, using the pressure-dependence of the intensities to distinguish the lines of [Formula: see text] from the many lies due to electronic transitions of H2 in the same region. The lines were assigned by means of calculations with a large vibration–rotation basis, using a Morse-based discrete variable representation for the vibrations. Eight coefficients in the Meyer–Botschwina–Burton ab initio potential were adjusted in order to fit 621 lines of [Formula: see text] from this and previous work with a standard deviation of 0.118 cm−1.