Line positions and strengths of methane in the 2862 to 3000 cm −1 region

Abstract

Measurements of line center positions and strengths of 1591 absorptions of CH 4 in the 2862 to 3000 cm −1 region have been made at high resolution. New assignments have been determined for several components in the P14 and P15 manifolds of the ν 3 band of 12CH 4. The strength data of the allowed transitions in the ν 3 band have been analyzed to determine the band strength and the coefficients of the F factor. The strength data given by Pine (1976) were also included in the analysis. For the ν 3 band, a strength of 259.5 cm −2 atm −1 at 296 K was obtained. Many forbidden lines in the ν 3 band were also observed in the spectra Line strengths in the ν 3 band of 13CH 4 were determined from the spectra. The quantum assignments for the majority of the observed absorptions were not determined. These absorptions arise primarily from the bands 2 ν 2, ν 2 + ν 4, ν 2 + ν 3 − ν 2 and ν 3 + ν 4 − ν 4 for which there is presently little or no information.