Algebraic Study of XYn Molecules in Vibrationaly High Excited States

Oб определении внутримолекулярной потенциальной функции многоатомной молекулы H2S

In modern molecular physics, there are two basic methods of determining the intramolecular potential function of polyatomic molecules. The first method is ab initio calculations and the second is the so-called semi-empirical method in which the Hamiltonian parameters are varied by direct construction of the Hamiltonian matrix. In the present work, the second approach is discussed on the example of the XY2 three-atomic molecule of the C2v symmetry. On the one hand, it is extremely simple for implementation, and on the other hand, it considerably extends the capability of application of the traditional semi-empirical methods. The approach suggested involves two aspects that make it advantageo…

Determination of intramolecular potential functions : Application to hydrogen sulphide and methane

High Resolution Study of the v1 + 2v2 −v2 and 2v2 + v3 − v2 ”Hot” Bands and Ro-Vibrational Re-Analysis of the v1 + v2/v2 + v3/3v3 Poliad of the SO2 Molecule

The main goal of the present study was to analyse rotational stuctures of two excited vibrational states, (120) and (021). Because both the band, v1+2v2 and 2v2+v3 one are extremally weak, a special efforts were faired to record very weak hot bands, v1+2v2−v2 and 2v2+v3−v2.Both of those bands are located in the region of considerably more stronger combinational bands, v1 + v2 and v2 + v3. On that reason, as the first step of analysis, we made assignments of transitions belonging to these v1 + v2 and v2 + v3 bands. As the result of analysis, we were able to assign three times more transitions to the bands v1 + v2 and v2 + v3 than it was known in the before literature. After "cleaning" the ex…

High resolution study of the SO2 infrared spectra: calculation scheme for assignment of transitions in very weak ro-vibrational bands.

Generalized algebraic treatment for XY2 molecules : application to D2S.

Vibrational interactions and resonances in XY2 molecules of C2v symmetry. Algebraic application to D2S system.

On the 'expanded local mode' approach applied to the methane molecule: isotopic substitution CH2D2 <--- CH4

International audience; On the basis of a compilation of the 'expanded local mode' model and the general isotopic substitution theory, sets of simple analytical relations between different spectroscopic parameters (harmonic frequencies, anharmonic coefficients, ro-vibrational coefficients, different kinds of Fermi- and Coriolis-type interaction parameters) of the CH2D2 molecule are derived. All of them are expressed as simple functions of a few initial spectroscopic parameters of the mother, CH4, molecule. Test calculations with the derived isotopic relations show that, in spite of a total absence of initial information about the CH2D2 species, the numerical results of the calculations have…

On the determination of intramolecular potential functions : Application to hydrogen sulphide and methane

High resolution molecular spectroscopy of the sulfur-containing XY2 type molecules.

In this thesis, we analyzed the high resolution absorption molecular spectra of H2S, D2S, HDS and SO2 registered for the first time or with better experimental characteristics as compared with those registered before. For the first time in the practice of rotation-vibrational spectroscopy in the frame of the devel- oped method of "global ftting" the analysis of 22 bands (as a whole more than 9700 rotation- vibrational lines) of D2S molecule is realized. This method of "global fitting" is developed with regard to molecules of Cs symmetry; on this basis a simultaneous analysis of all the known up to the present rotation-vibrational spectra of HDS molecule is realized. The SPGF method is appli…