A 6Σ–6Σ TRANSITION IN CrH

The infrared band system of CrH has been photographed at high dispersion. Rotational analyses of the 0–0 and 0–1 bands are given. The transition is shown to be a 6Σ+–6Σ+. The upper 6Σ-state shows an extended perturbation. Rotational and vibrational constants for the two states are given. The application of theoretical expressions for the fine structure splitting in 6Σ-states is discussed and approximate values of the splitting constants in the observed states have been derived. The corresponding system of the isotope molecule CrD was also photographed and a vibrational analysis has been carried out. Finally the electronic configurations of the molecular states and the nature of the perturbing state are discussed. The ultraviolet systems of CrH are briefly mentioned.