Abstract
The infrared spectra of matrix‐isolated water in neon, argon, krypton, and xenon solids near 4°K have been obtained between 29 and 60 cm—1. The few lines that are observed depend strongly on the matrix material and are in good agreement with lines in the v1 and v2 vibrational bands. This observation confirms the widely held belief that the fine structure in the near‐infrared spectrum has a rotational or hindered‐rotational origin.