Coriolis resonance in the v₂⁰ + v₆^±1,v₅^∓1 + v₆^∓1 infra-red bands of methyl chloride

Abstract

The v ₂ ⁰ + v ₆ ^±1 and v ₅ ^∓1 + v ₆ ^∓1 perpendicular bands of methyl chloride have been studied under high resolution, and found to be coupled by a strong xy Coriolis interaction, with eventual level crossing. Evidence is given for the K numbering of the branches and earlier assignments for v ₅ ^∓1 + v ₆ ^∓1 [1] are corrected. Several minor perturbations and unassigned lines remain to be clarified.