Since the Royal Society Discussion Meeting on in 2000, the laboratory spectroscopy of has entered a new regime. For the first time, transitions of above the barrier to linearity have been observed. A highly sensitive near-infrared spectrometer based on a titanium:sapphire laser and incorporating a dual-beam, double-modulation technique with bidirectional optical multi-passing has been developed in order to detect these transitions, which are more than 4600 times weaker than the fundamental band. We discuss our recent work on the , , , and combination bands and the , , and overtone bands. Experimentally determined energy levels provide a critical test of ab initio calculations in this challenging energy regime (greater than 10 000 cm−1). By comparing the experimental energy levels and theoretical energy levels from ab initio calculations in which the adiabatic and relativistic corrections are incorporated, the extent of higher-order effects such as non-adiabatic and radiative corrections is revealed.
One contribution of 26 to a Discussion Meeting Issue ‘Physics, chemistry and astronomy of H3+’.
- © 2006 The Royal Society