High-resolution infrared spectroscopy of solid hydrogen

A rich spectrum composed of hundreds of sharp features (HWHM ~< 20 MHz) has been observed in the fundamental Q branch of solid H2, representing the first case of solid phase linear spectroscopy in which the high-resolution capabilities of laser spectroscopy have been fully exploited. These features are interpreted as splittings of o-H2 pairs based on the work by Hardy, Berlinsky, and Harris