Analysis of Doppler-limited spectra of the CO stretch fundamental of CD 3OH

Abstract

Doppler-limited linewidth diode laser spectra of the low- J P and R branches of the ν 4 band (CO stretch) of CD 3OH were recorded and analyzed. Hindered internal rotation and molecular asymmetry are handled by exact matrix diagonalization. Fermi resonance between ν 4 and the τ = 1, n = 3 and n = 4 torsional levels of the ground vibration state was found to be responsible for several anomalous spectral features. Direct LMS fitting of the data to a set of 11 excited-state parameters lead to the assignment of 160 lines with a rms error of ±0.00088 cm −1.