The He-H complex. II. Infrared predissociation spectrum and energy term diagram.

The rotationally resolved infrared (IR) spectrum of the He-H complex has been measured in a cryogenic ion trap experiment at a nominal temperature of 4 K. Predissociation of the stored complex has been invoked by excitation of the degenerate ν mode of the H sub-unit using a pulsed optical parametric oscillator system. An assignment of the experimental spectrum became possible through one-to-one correlations with bands of the spectrum theoretically predicted in Paper I [Harding et al.