A new analysis of the ν2 fundamental band of H2O+*

This paper reports that the absorption spectra of H2O+ have been measured by tunable mid-infrared diode laserspectroscopy in the spectral range of 1100–1380 cm-1. The H2O+ ions are generated in an AC glow discharge of the gaseous mixtures of H2O/He and detected with the velocity modulation technique. Forty new lines are assigned to theν2 fundamental band of H2O+( X-bar 2B1). The observed lines together with other data published previously are fitted to the standard effective Hamiltonian of an asymmetric top, yielding a set of improved rotational constants, spin-rotation constants and their quartic and sextic centrifugal distortion constants for the ν2=1 vibrational state of H2O+. (atomic and molecular physics)