Microwave and submillimeter-wave rotational spectrum of methyl alcohol in the ground torsional state
The frequencies of 440 transitions of the spectrum of the ground torsional-vibrational state of methyl alcohol have been measured in the microwave and submillimeter regions, 130 of these belonging to the main isotopomer CH 3OH ( J ≤ 42, K ≤ 8), 190 to the isotopomer CD 3OH ( J ≤ 37, K ≤ 10), and 120 to CD 3OD ( J ≤ 27, K ≤ 5). For the first time, all the transitions were identified on the basis of directly calculated frequencies. These results were obtained through the use of a new effective torsional-rotational Hamiltonian. Its parameters were calculated based on the frequencies of all earlier known and new transitions of microwave and submillimeter-wave spectra of the ground torsional-vibrational state of methanol. The root-mean-square deviation is 710 kHz (800 lines) for the main isotopomer, 144 kHz (370 lines) for CD 3OH, and 316 kHz (150 lines) for CD 3OD.