Top-Top Interaction in Hexa-Deutero Dimethyl Selenide from the Microwave Spectrum in the First Excited Torsional States

1976 ◽  
Vol 31 (11) ◽  
pp. 1413-1418
Author(s):  
G. K. Pandey ◽  
H. Lutz ◽  
H. Dreizler
Keyword(s):  
Fine Structure ◽  
Least Squares ◽  
Internal Rotation ◽  
Degrees Of Freedom ◽  
Molecular Model ◽  
Microwave Spectrum ◽  
Two Degrees Of Freedom ◽  
Least Squares Fit ◽  
Dimethyl Selenide ◽  
Three Degrees Of Freedom

Abstract An analysis of the internal rotation fine structure for the rotational transitions of hexa-deutero dimethyl selenide in the first excited torsional states is presented in terms of a molecular model with two degrees of freedom for the internal rotation or torsion of the two tops in addition to the three degrees of freedom for the overall rotation. By a least squares fit of the multiplet splittings of ten transitions in the vn=11 and nine transitions in the ṽn=12 excited torsional states, the following parameters have been obtained: F3=1493±9 cal mol-1; ϑ=50°1′±7′ V12′=28.4±0.3 cal mol-1. The splitting of the fine structure components could be nicely fitted, but not their absolute frequencies and the seperation between the two multiplets.

An Extension of Rayleigh's Principle

1994 ◽  
Vol 22 (2) ◽  
pp. 83-90
Author(s):  
Alfonso Díaz-Jiménez ◽  
Gentil A. Estévez-Bretón
Keyword(s):  
Present Article ◽  
Degrees Of Freedom ◽  
Mechanical Systems ◽  
Natural Generalization ◽  
Vibrational Frequencies ◽  
Exact Results ◽  
Two Degrees Of Freedom ◽  
Elegant Method ◽  
Three Degrees Of Freedom

Steidel's extension of Rayleigh's method for calculating the natural vibrational frequencies of mechanical systems with two degrees of freedom provides an elegant method to obtain exact results. In the present article this approach, which perhaps has not been exploited as much as it could be, is first reviewed and then several examples of the procedure are given. An extension of the method to three degrees of freedom is presented, and a natural generalization of Rayleigh's principle is suggested.

Eine Analyse der Methyltorsionsfeinstruktur von Rotationsspektren in angeregten Zuständen der S-S-Torsion beim Trideutero-methyl-methyldisulfid / An Analysis of Methyltorsion Finestructure in Rotational Spectra of Excited States of S-S-Torsion of Trideutero-methyl-methyldisulfide

1974 ◽  
Vol 29 (9) ◽  
pp. 1335-1344 ◽  
Author(s):  
M. Kuhler ◽  
L. Charpentier ◽  
D. Sutter ◽  
H. Dreizier
Keyword(s):  
Fine Structure ◽  
Excited States ◽  
Degrees Of Freedom ◽  
Microwave Spectrum ◽  
Eine Analyse ◽  
Rotational Spectra ◽  
Methyl Torsion ◽  
Internal Degrees Of Freedom

The microwave spectrum of CH3SS CD3 was investigated in the range of 5 -40 GHz. Rotational spectra in different states of the S-S-torsion were assigned. The methyl torsion fine structure of these spectra was measured and compared with calculations based on a Hamiltonian formulated for a model with two internal degrees of freedom, the methyl and S-S-torsion.

The gas-phase infrared spectra of nitromethane and methyl boron difluoride; fine structure caused by internal rotation

1968 ◽  
Vol 304 (1477) ◽  
pp. 135-155 ◽  
Keyword(s):  
Fine Structure ◽  
Gas Phase ◽  
Internal Rotation ◽  
Infrared Spectra ◽  
Degrees Of Freedom ◽  
Coupling Constants ◽  
Modes Of Vibration ◽  
Simplifying Assumptions ◽  
Boron Difluoride ◽  
Vibration Rotation

The gas-phase infrared spectra of nitromethane and methyl boron difluoride have been analysed in some detail. The various skeletal modes of vibration, and the vibrations of the methyl group with dipole changes parallel to the carbon–nitrogen and carbon–boron axes respectively, have vibration–rotation band contours which are of the expected type as calculated from the moments of inertia for overall rotation of the molecules. The perpendicular vibrations of the methyl groups all have complex contours, and in a number of cases widely-spaced fine structure lines are present. These can only be accounted for in terms of the internal rotation degrees of freedom. This is as expected because in classical terms the internal rotation frequencies modulate the oscillating vibrational dipole moment of these (and only these) methyl vibrations; in quantum-mechanical terms this leads to addi­tional transitions involving changes in the quantum number for internal rotation. These perpendicular methyl vibration bands have complex rotational structure because of interaction of the internal rotation degree of freedom with the overall rotations of these asymmetric top molecules. Nevertheless their main Q -branch features have been rather successfully analysed in terms of a theoretical model in which it is assumed that the internal rotation is free, and that the degeneracies of these perpendicular modes are retained. The former is expected to be a good approximation because of the known very low barriers to internal rotation. Some unresolved complexities, particularly towards the centres of the bands, may be caused by deviations from these simplifying assumptions. Analyses of the bands in this manner leads to information about the band origins and to reasonable values for the Coriolis coupling constants of the degenerate vibrations.

Torsion-Torsion Interaction in the Microwave Spectrum of Dimethylether

1976 ◽  
Vol 31 (8) ◽  
pp. 1026-1028 ◽  
Author(s):  
H. Lutz ◽  
H. Dreizler
Keyword(s):  
Fine Structure ◽  
Internal Rotation ◽  
Microwave Spectrum ◽  
Potential Parameters

Abstract We report an analysis of the torsional fine structure of rotational lines of (CH3)2O in excited torsional states leading to the potential parameters V3 and V′12 of a Hamiltonian for the overall-and internal rotation.

A Contribution to the Microwave Spectrum of Dimethyl Selenide

1980 ◽  
Vol 35 (11) ◽  
pp. 1223-1230 ◽  
Author(s):  
H. Dreizler ◽  
E. Fliege ◽  
G. K. Pandey
Keyword(s):  
Internal Rotation ◽  
Microwave Spectrum ◽  
Centrifugal Distortion ◽  
Microwave Spectra ◽  
Isotopic Species ◽  
Dimethyl Selenide

Abstract The microwave spectra of five isotopic species of dimethyl selenide have been measured and analysed for centrifugal distortion and internal rotation by PAM and IAM.

Torsions-Vibrations-Rotations-Wechselwirkung im Mikrowellenspektrum von Methylthiocyanat

1974 ◽  
Vol 29 (5) ◽  
pp. 797-803 ◽  
Author(s):  
U. Andresen ◽  
H. Dreizier
Keyword(s):  
Ground State ◽  
Vibrational State ◽  
Degrees Of Freedom ◽  
Molecular Model ◽  
Microwave Spectrum ◽  
Potential Parameter ◽  
Pure Torsion ◽  
Excited Vibrational State ◽  
The Absolute ◽  
Good Agreement

Abstract The microwave spectrum of methylthiocyanate is reinvestigated on the basis of a molecular model with five degrees of freedom, three for the overall rotation, one for the torsion and one for another vibration. It was possible to fit the splittings of all four measured states (ground state, first excited torsional and vibrational state and second excited vibrational state) with one set of parameters but it was impossible to fit the absolute line frequencies. The value for the potential parameter of the pure torsion V3 is in good agreement with that determined on the basis of the rigid framerigid top (RF-RT) model from the ground state.

Microwave Spectrum and Barrier to Internal RotationinCH3COC15N

1977 ◽  
Vol 32 (7) ◽  
pp. 761-764 ◽  
Author(s):  
G. K. Pandey ◽  
H. Dreizler
Keyword(s):  
Least Squares ◽  
Potential Barrier ◽  
Ground State ◽  
Microwave Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Least Squares Fit ◽  
Barrier Parameter ◽  
Centrifugal Distortion Constants

Abstract The ground state rotational spectra of the 15N isotopic species of acetyl cyanide have been measured in the region from 8 to 40 GHz. The rotational and centrifugal distortion constants have been determined by a least squares fit to about 38 transition frequencies with J ≦ 14. The potential barrier parameter V3 and the angle a between the top axis and the 'a-axis' have been determined by a least squares of the (A-E) splittings of about 27 transitions. The methyl top moment of inertia was fixed at 3.14 amu Å2

scholarly journals FROM DI-NUCLEUS TO MONO-NUCLEUS: NECK EVOLUTION IN FUSION OF MASSIVE SYSTEMS

2009 ◽  
Vol 18 (10) ◽  
pp. 2169-2174 ◽  
Author(s):  
YASUHISA ABE ◽  
CAIWAN SHEN ◽  
DAVID BOILLEY ◽  
BERTRAND G. GIRAUD
Keyword(s):  
Time Scales ◽  
Heavy Ions ◽  
Degrees Of Freedom ◽  
The Other ◽  
Fusion Process ◽  
Two Degrees Of Freedom ◽  
Mass Asymmetry ◽  
Langevin Approach ◽  
Fluctuation Dynamics ◽  
Three Degrees Of Freedom

Dynamics of the neck degree of freedom during fusioning process between heavy ions is studied. Time scales of the three degrees of freedom (the relative distance, the neck and the mass-asymmetry) are studied, showing an early equilibration of the neck. This means that a di-nucleus formed by the incident combination of ions quickly forms a mono-nucleus with a superdeformation during the fusion process and that the other two degrees of freedom have to be solved in a coupled way. A brief introduction of Langevin approach and dissipation-fluctuation dynamics is also given and of the application to the synthesis of the superheavy elements.

The Characterization of a Grain Boundary by Transmission Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 436-437 ◽  
Author(s):  
R.J. Horylev ◽  
L.E. Murr
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundary ◽  
Degrees Of Freedom ◽  
Boundary Plane ◽  
The Other ◽  
Two Degrees Of Freedom ◽  
Transmission Electron ◽  
Three Degrees Of Freedom

Read has shown that an arbitrary grain boundary has five degrees of freedom associated with it. Three degrees of freedom are necessary to describe the orientation of one grain with respect to the other, while the remaining two degrees of freedom position the boundary plane between the adjacent grains.Figure 1(a) depicts a general twin boundary-grain boundary intersection. The degrees of freedom for the grain boundary are represented by (HKL)1, (HKL)2, Θ, θGB, ø. Two degrees of freedom are contained in the surface orientations of the grains.

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