Laboratory spectroscopy of H3+
Department of Chemistry and Department of Astronomy & Astrophysics, University of Chicago, USA
The experimental determination of the low-lying rovibrational energy levels of H3+ using high-resolution, high-sensitivity infrared laser spectroscopy has confirmed this ion's equilateral triangle equilibrium geometry, provided direct information on its quantum mechanical characteristics, and enabled its extensive study in planetary ionospheres and in the interstellar medium.
Since the discovery of the v2 fundamental band, the laboratory spectroscopy of H3+ has been pushed to higher energies through the study of vibrational overtones, combination bands, and hot bands. We review the twenty years of laboratory spectroscopy of this important ion, and discuss our recent work on the v1+2v22 band.