Algebraic Description of Anharmonic Stretching Vibrations.
نویسندگان
چکیده
A U(2) algebraic model is presented to describe stretching vibrations of XYn (n = 2, 3, and 4) systems, where anharmonic interactions between the bond modes are considered. This model in a limit corresponds to an anharmonically coupled local-mode model. As an example, the model for a molecule XY4 is applied to recently observed spectra of methane in both gas and liquid phases, and the results obtained are in good agreement with the experiments. Copyright 1999 Academic Press.
منابع مشابه
Infrared Spectrum of Toluene: Comparison of Anharmonic Isolated-Molecule Calculations and Experiments in Liquid Phase and in a Ne Matrix.
First-principles anharmonic calculations are carried out for the CH stretching vibrations of isolated toluene and compared with the experimental infrared spectra of isotopologues of toluene in a Ne matrix at 3 K and of liquid toluene at room temperature. The calculations use the vibrational self-consistent field method and the B3LYP potential surface. In general, good agreement is found between...
متن کاملCH Stretching Region: Computational Modeling of Vibrational Optical Activity.
Most organic compounds provide vibrational spectra within the CH stretching region, yet the signal is difficult to interpret because of multiple difficulties in experiment and modeling. To better understand various factors involved, the ability of several harmonic and anharmonic computational approaches to describe these vibrations was explored for α-pinene, fenchone, and camphor as test compou...
متن کاملSymmetry-Adapted Algebraic Description of Stretching and Bending Vibrations of Ozone
The vibrational excitations of ozone, including both bending and stretching vibrations, are studied in the framework of a symmetry-adapted algebraic approach. This method is based on the isomorphism between the U(2) algebra and the one-dimensional Morse oscillator, and the introduction of point group symmetry techniques. The use of symmetry-adapted interactions, which in the harmonic limit have...
متن کاملAlgebraic Models and Quantum Deformations in Molecular Thermodynamics
Lie-algebaic and quantum-algebraic techniques are used in the analysis of thermodynamic properties of molecules and solids at high temperatures. In the framework of the algebraic models, the local anharmonic effects are described by a Morse-like potential, associated with the SU(2) algebra. The vibrational high-temperature properies, such as mean energy and specific heat, are studied in terms o...
متن کاملExtrapolation of water and formaldehyde harmonic and anharmonic frequencies to the B3LYP/CBS limit using polarization consistent basis sets
The harmonic and anharmonic frequencies of fundamental vibrations in formaldehyde and water were successfully estimated using the B3LYP Kohn-Sham limit. The results obtained with polarization- and correlation-consistent basis sets were fitted with a two-parameter formula. Anharmonic corrections were obtained by a second order perturbation treatment (PT2). We compared the performance of the PT2 ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of molecular spectroscopy
دوره 195 1 شماره
صفحات -
تاریخ انتشار 1999