This review covers the work of the three decades since the first spectroscopic identification
of the H 3+ molecular ion outside of the laboratory in 1988, in the auroral atmosphere of the …

Molecular ions have long been considered key intermediates in the evolution of molecular
complexity in the interstellar medium. However, owing to their reactivity and transient nature …

In what has been described as the fourth age of quantum chemistry, variational nuclear
motion programs are now routinely being used to obtain the vibration-rotation levels and …

New MiZo line lists are presented for the D2H+ and D isotopologues of H. These line lists
plus the existing H MiZATeP and the ST H2D+ line lists are updated using empirical energy …

H 3+ and two of its deuterated variants have been trapped and cooled in a 4 K trap machine,
and their fundamental vibrational transitions probed with the laser induced reactions …

Calculation of the rotation-vibration spectrum of ${{\rm {H}}} _ {3}^{+} $, as well as of its
deuterated isotopologues, with near-spectroscopic accuracy requires the development of …

The performance of sensitive spectroscopic methods in the mid-IR is often limited by fringing
due to parasitic etalons and the background noise in mid-infrared detectors. In particular, the …

A sub-Doppler rovibrational spectroscopic survey of H 3+ has been conducted which
included 36 transitions in the ν 2← 0 fundamental band, 15 transitions in the 2 ν 2 2← ν 2 …

In our previous work on the Lamb-dips of the ν 2 fundamental band transitions of H 3+⁠, the
saturated absorption spectrum was obtained by third-derivative spectroscopy using …

Velocity Modulation Spectroscopy (VMS) is arguably the most important development in the
20th century for spectroscopic study of molecular ions. For decades, interpretation of VMS …