Abstract
The reflection spectra of H2S frost in the near infrared region (1.6–4 μm), as a function of temperature to 62 °K, were measured. Analyses of these spectra were made, and assignments for the most intense combinations attempted. Dramatic changes in spectra are observed from 62–143 °K, connected with a phase transition between a tetragonal, low‐temperature phase and a cubic, high‐temperature phase, occurring at 125±5 °K. The data present evidence for only two phases being involved for H2S frost.