Global Fit of Torsion–Rotational Transitions in the First Three Torsional States of CH3OD

Abstract

A global fit of the observed high-resolution microwave (MW), millimeter-wave (MMW), and Fourier transform far-infrared (FIR) spectra for CH3OD has been performed using a reduced torsion–rotational Hamiltonian that is obtained from the one-large-amplitude internal-rotation model. The CH3OD data set contains 460 MW and MMW transitions with two or fewer quanta in the torsion, vt ≤ 2, and 2348 Fourier transform FIR transitions with vt ≤ 1 and J ≤ 21. The MW and MMW transitions have been fitted with a root-mean-square (rms) deviation of 0.11 MHz (0.098 MHz for J ≤ 10) while FIR transitions have a rms deviation of 0.0002 cm−1. These deviations are approximately equal to the experimental uncertainties, indicating that the MW, MMW, and FIR spectral transitions have been fit to experimental accuracy.