Analysis of the CH3D Nonad from 2000 to 3300 cm−1

Preliminary analysis of CH3D from 3250 to 3700cm−1

“…3 Theoretical framework The theoretical framework of the present work is the same as the one already described in our previous reports [11] and [12]. Only basic or new features will be repeated or detailed here.…”

“…Measurements from dierent spectra were then combined and averaged to produce the observed values. Examples of this process are shown in the earlier studies of the Triad [11] and Nonad [12]. μm could be as large as =0.0015 cm =1 with the gas sample at 90 torr.…”

“…2 Experimental details The spectral data for the present study came from our previous analysis of the Nonad [12], and so experimental details are only briey repeated here. The spectra were recorded at 0.011 cm =1 resolution using the McMath-Pierce Fourier Transform Spectrometer congured with InSb detectors.…”

“…The states drawn with doubled lines have multiple sub-components; for example, 3ν 6 has three (A 1 , A 2 and E) sub-levels, and ν 3 + 2ν 6 has two (A 1 and E). The vibrations are redrawn in the three other columns to show the expected Fermi and Coriolis interactions based on prior studies of the Triad [11] and Nonad [12]. As a preliminary approach, the Enneadecad polyad can be grouped into three sets.…”

“…Accurate representation of the positions and intensities of this molecule requires that the polyad scheme be used. The six fundamentals of CH 3 D are grouped into two polyads; the Triad (610 μm) is composed of the three lowest fundamentals (ν 6 , ν 3 , ν 5 ) [11] while the Nonad (35 μm) contains the three upper fundamentals (ν 2 , ν 4 , ν 1 ) with three combination bands (ν 3 + ν 6 , ν 5 + ν 6 , ν 3 + ν 5 ) and three overtones (2ν 6 , 2ν 3 , 2ν 5 ) [12]. The common eective Hamiltonian is developed so that vibrational states within each polyad can be treated simultaneously in order to account for numerous interactions between the energy levels.…”