Knowledge Bank

We have extended the sub-Doppler spectroscopic study of the $\nu 8$ C-O stretching fundamental band of methanol with a dual-mode CO$2$-laser/microwave-sideband spectrometer}}, 1052 (2004).}. A further 492 transitions, including a number of overlapped and doublet lines unresolved in the Doppler-limited spectra of the broadband scanning mode, have been observed as saturation dips with a resolution of 0.4 MHz in the sub-Doppler detection mode and their frequencies have been measured with accuracy of order $\pm$200 kHz. For $K$ from 1 to 5, energy term values for the excited-state levels of these $A$- and $E$-species transitions have been determined using known ground-state energies and have been fitted to Taylor-series expansions in powers of $J(J+1)$ to yield accurate expansion coefficients. The present, together with previous sub-Doppler measurements}}, 2068 (2000).}, provide a high accuracy database for CH$3$OH, with application to methanol vibrational interaction studies and the interpretation of the optically pumped far-infrared laser emission spectrum.