Lowest Overtone and Combination Levels of DCCI: The Fermi Resonance v3 = 1/v5 = 2.
The infrared spectrum of deuterated monoiodoacetylene DCCI in the region of 220-550 cm-1 has been studied at a resolution of 0.0020 cm-1. The hot bands nu3 <-- nu15 and 2nu0,25 <-- nu15 have been analyzed by considering especially the Fermi resonance v3 = 1/v5 = 2. In the next layer of the hot bands (nu3 + nu5)1 <-- nu3, (nu3 + nu5)1 <-- 2nu0,25 and 3nu1,35 <-- 2nu25 the same Fermi resonance appears between v3 = v5 = 1 and v5 = 3. In addition, various l resonances at the overtone levels have been considered. As a result, the vibrational and rotational constants for the level systems v3 = 1/v5 = 2 and v3 = v5 = 1/v5 = 3 together with the resonance parameters have been obtained. Copyright 1999 Academic Press.
Simultaneous Analysis of the Rovibrational Levels υ4=1, 2, and 3 of HCCI and DCCI Based on Infrared Spectra
Abstract The energy levels υ 4 =1, υ 4 =2, and υ 4 =3 of DCCI have been analyzed by using the fundamental ν 4 1 (470–520 cm −1 ) and the overtone 2ν 4 0 (955–1005 cm −1 ) bands together with the hot bands 2ν 4 0,2 ←ν 4 1 , 3ν 4 1,3 ←2ν 4 0,2 , and 3ν 4 1 ←ν 4 1 . In the case of HCCI the previously studied hot bands connected to ν 4 have been completed by adding 3ν 4 1 ←ν 4 1 into the analysis. The various l -type resonances have been taken into account in the analyses of both the isotopomers. Furthermore, the Coriolis resonance between the close-lying ν 3 and ν 4 of DCCI has been considered. Altogether, accurate values for the molecular constants and the resonance parameters have been obtained from simultaneous analysis and they have been compared with those from separate analyses for different levels.
Effective Hamiltonian for polyatomic linear molecules
Abstract The leading terms of an effective Hamiltonian for a linear molecule in a given vibrational state are presented up to κ 10 T v order of magnitude, whereby higher-order l -dependent terms such as H 12.0 , H 8.0 , and H 8.2 have been neglected because in spectroscopic application they are of minor importance. This Hamiltonian therefore includes all those l -type interactions which could contribute to the fitting procedure, within a vibrational state where one or more bending vibrations are excited.