The infrared spectrum of CH3D between 900 and 3200 cm(-1): extended assignment and modeling

The high resolution infrared spectrum of CH3D in the region from 900 to 320 0 cm(-1) has been analyzed on the basis of Fourier transform spectra record ed at Kitt Peak and at Giessen, A theoretical model for an effective hamilt onian in terms of irreducible tensor operators recently adapted to symmetri c top molecules has been used in order to consider simultaneously all avail able transitions between the lowest three polyads of the molecule: the Grou nd State (G.S.), the Triad (three interacting fundamental bands in the 8 mu m region) and the Nonad (nine interacting bands in the 4 mu m region). A p reliminary simultaneous fit of 3467 Triad-G.S., 5208 Nonad-G.S., and 2487 N onad-Triad (bot band) transition wavenumbers has been done. The standard de viations achieved were 2.1, 4.7 and 4.3 x 10(-3) cm(-1), respectively. A pr eliminary analysis of the transition intensities was also undertaken at a l evel of precision of the order of 5% or better. (C) 2000 Elsevier Science B .V. All rights reserved.