Molecular Vibration Analysis of the Cage-Like Molecules β-P4S5, As4S5, P4S7, and AS2P2S7

1983 ◽  
Vol 38 (9) ◽  
pp. 987-994 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
H. Motz ◽  
C. Wibbelmann
Keyword(s):  
Force Field ◽  
Molecular Vibration ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Unknown Compound ◽  
Amplitude Correction ◽  
Symmetry Coordinates ◽  
Complete Set ◽  
The Mean ◽  
Initial Force

Abstract The cage-like molecules β-P4S5 , As4 S5 , P4S7 and As2P2S7 are all supposed to have C2v -symmetry. A normal coordinate analysis was performed for those molecules, based on a very simple initial force field with three numerical parameters and valence coordinates including redundancies. A complete set of symmetry coordinates is given. The force field was refined by adjusting the symmetry force constants to fit exactly a set of observed frequencies. This was used to calculate the mean amplitudes of vibration and perpendicular amplitude correction coefficients. The standard thermodynamical values derived from spectroscopic data are also given. A set of frequencies was calculated for the so far unknown compound P4S6 .

Schwingungsberechnungen der käfigstrukturierten Moleküle P4Se3 , AS4S3, As4Se3 und PAs3S3 / Molecular Vibration Analysis of the cage-like Molecules P4Pe3, As4S3, As4Se3 and PAs3S3

1981 ◽  
Vol 36 (8) ◽  
pp. 846-849 ◽  
Author(s):  
W. Brockner ◽  
M. Somer ◽  
B. N. Cyvin ◽  
S. J. Cyvin
Keyword(s):  
Force Field ◽  
Coupling Constants ◽  
Molecular Vibration ◽  
Coriolis Coupling ◽  
Normal Coordinate ◽  
Cage Structure ◽  
Mean Amplitudes Of Vibration ◽  
The Mean ◽  
Initial Force ◽  
Thermodynamical Functions

AbstractnThe P4Se3, As4S3, As4Se3 and PAs3S3 molecules are supposed to have a cage-structure of the C3V symmetry. Normal coordinate analyses for these molecules were performed, based on a very simple initial force field transferred from P4S3. The force field was refined by adjusting the symmetry force constants to fit exactly observed frequencies. The force fields were used to calculate the mean amplitudes of vibration and Coriolis coupling constants. The standard thermodynamical functions from spectroscopic data are also given.

Schwingungsberechnungen des käfigstrukturierten P4S3

1980 ◽  
Vol 35 (10) ◽  
pp. 1062-1065 ◽  
Author(s):  
S. J. Cyvin ◽  
J. Brunvoll ◽  
B. N. Cyvin ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Force Field ◽  
Coriolis Coupling ◽  
Coupling Coefficients ◽  
Normal Coordinate ◽  
Cage Structure ◽  
First Order ◽  
Symmetry Coordinates ◽  
Complete Set ◽  
The Mean ◽  
Initial Force

Abstract The P4S3 molecule is supposed to have a cage-structure of C3V symmetry. A normal coordinate analysis for this molecule was performed, based on a very simple initial force field with three numerical parameters and valence coordinates including redundancies. A complete set of independent symmetry coordinates is given. The force field was refined by adjusting the symmetry force constants to fit exactly a set of observed frequencies. This final force field was used to calculate the first-order Coriolis coupling coefficients and the mean amplitudes of vibrations. The standard thermodynamics functions from spectroscopic data are also given.

Schwingungsberechnungen der Species Ti2Cl102− , Ti2Cl9− und TiCl5− / Molecular Vibration Analysis of Ti2Cl102− , Ti2Cl9− and TiCl5−

1979 ◽  
Vol 34 (3) ◽  
pp. 362-368 ◽  
Author(s):  
A. F. Demiray ◽  
W. Brockner ◽  
B. N. Cyvin ◽  
S. J. Cyvin
Keyword(s):  
Potential Energy ◽  
Matrix Method ◽  
Vibration Analysis ◽  
Molecular Model ◽  
Molecular Vibration ◽  
Normal Coordinate ◽  
Energy Distributions ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
The Mean

AbstractNormal coordinate analyses of the chlorotitanate ions Ti2Cl102−Ti2Cl9− - and TiCl5− have been carried out following Wilson's FG matrix method. The final force constants are given in terms of symmetry coordinates, which are thoroughly specified for a Ti2Cl9− molecular model. Assignments of the vibrational frequencies of the title compounds are proposed, and the corresponding potential energy distributions are given. The final force fields were used to calculate the mean amplitudes of vibration, of which those of TiCl5− and selected values of Ti2Cl102− andTi2Cl9− are reported.

Condensed Aromatics. Part III. In-Plane Molecular Vibrations of Pyrene

1979 ◽  
Vol 34 (7) ◽  
pp. 876-886 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
J. Brunvoll ◽  
J. C. Whitmer ◽  
P. Klaeboe ◽  
...  
Keyword(s):  
Force Field ◽  
Molecular Model ◽  
Electron Diffraction Data ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
Test Molecule ◽  
Out Of Plane ◽  
Complete Set ◽  
The Mean ◽  
Parameter Approximation

A new force field is developed for the in-plane vibrations of condensed aromatics using pyrene as a test molecule. Only five parameters are employed in this force field, which improves a four- parameter approximation previously investigated. Still the simple five-parameter approximation gives calculated vibrational frequencies in good agreement with those from the more elaborate Califano-Neto force field.In the course of the normal coordinate analysis the Hüekel molecular orbitals have been de­duced. The CC stretching parameters were modified by means of the calculated bond orders. A complete set of independent symmetry coordinates (both in-plane and out-of-plane) for the pyrene molecular model was developed.New experimental data from infrared and Raman spectra for pyrene are reported.Also the mean amplitudes of vibration are studied in detail. It is concluded that the simple five-parameter approximation gives reliable mean amplitudes, which undoubtedly are accurate enough for the interpretation of gas electron diffraction data.Finally the calculated frequencies and mean amplitudes of benzene are given. The mean amplitudes are again found to be very accurate in spite of some substantial inaccuracies in the frequencies.

Schwingungsberechnungen der käfigstrukturierten Molekülionen P73-, AS73- und Sb73-

1986 ◽  
Vol 41 (3) ◽  
pp. 549-552 ◽  
Author(s):  
B. N. Cyvin ◽  
S. J. Cyvin ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Force Field ◽  
Coupling Constants ◽  
Potential Energy Distribution ◽  
Coriolis Coupling ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
First Order ◽  
The Mean ◽  
Title Molecule ◽  
Initial Force

Normal coordinate analyses for the cage-like molecule ions P73-, As73- and Sb73- with C3 symmetry were performed, based on a very simple initial force field with three numerical parameters transferred from P4S3. FIR frequencies of Sb73- have been recorded. The force field was refined by adjusting the symmetry force constants to fit the observed frequencies. The final force fields were used to calculate the potential energy distribution terms (PED), the mean amplitudes of vibration and the first-order Coriolis coupling constants for the title molecule ions.

Molecular Vibrations of Gallium Trichloride Monomer with Application of the Keating Bending

1985 ◽  
Vol 40 (7) ◽  
pp. 714-718 ◽  
Author(s):  
B. N. Cyvin ◽  
S. J. Cyvin ◽  
G. Diaz ◽  
T. Mogstad ◽  
E. Rytter
Keyword(s):  
Force Field ◽  
Field Approximation ◽  
Normal Coordinate ◽  
Frequency Shifts ◽  
Mean Amplitudes Of Vibration ◽  
Central Force Field ◽  
Valence Force Field ◽  
New Type ◽  
The Mean ◽  
Gallium Trichloride

The vibrational spectra and previous normal coordinate analyses of GaCl3 are reviewed. The valence force field (VFF), Keating force field (KFF) and central force field (CFF) are investigated, taking into account isotopic frequency shifts and the mass influence on Coriolis constants. It seems that KFF is an appropriate force field approximation. In its definition a new type of internal coordinates, the Keating's bending, is invoked. A final force Field is tentatively determined and used to calculate the mean amplitudes of vibration.

Schwingungsberechnungen des Hexathiometadiphosphatanions P2S62-

1988 ◽  
Vol 43 (5) ◽  
pp. 494-496 ◽  
Author(s):  
Lothar Ohse ◽  
Wolfgang Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Field Potential ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Initial Force

A normal coordinate analysis for the Hexathiometadiphosphate anion P2S62- was performed, based on a simple initial force field. The force field was refined by adjusting the symmetry force constants to approximate the observed frequencies. The final force field, potential energy distribution (PED) and mean amplitudes of vibration are also given. Based on the normal coordinate analysis a new assignment of the P2S62- frequencies is proposed.

Normal coordinate analysis of diacetylene and dicyanoacetylene

1969 ◽  
Vol 22 (6) ◽  
pp. 1123 ◽  
Author(s):  
K Ramaswamy ◽  
K Spinivasan
Keyword(s):  
Potential Energy ◽  
Interaction Force ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Characteristic Set ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
The Mean ◽  
Energy Constants

The potential energy constants of diacetylene and dicyanoacetylene were obtained by the method of ?characteristic set of valence coordinates? of Herranz and Castano. The values of the various interaction force constants were determined without any assumptions regarding force fields. The mean amplitudes of vibration for the various characteristic bonds were calculated by Cyvin's method. It is shown that the conventional set of symmetry coordinates, usually characterized by individual chromophores, leads to abnormally large values for the force constants in the case of dicyanoacetylene. Hence a different set of symmetry coordinates taking into account the whole unit of CC bonds has to be chosen to get a reasonable set of force constants.

scholarly journals Synthesis, Vibrational Spectra and Normal Coordinate Analysis of Cesium-Hexathiohypodiphosphate Cs4P2S6

1985 ◽  
Vol 40 (7) ◽  
pp. 709-713 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
C. Wibbelmann ◽  
R. Becker ◽  
W. Brockner ◽  
...  
Keyword(s):  
Force Field ◽  
Vibrational Spectra ◽  
Field Potential ◽  
Normal Coordinate Analysis ◽  
Coupling Constants ◽  
Potential Energy Distribution ◽  
Reaction Products ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Initial Force

The title compound has been prepared by elemental synthesis at high temperatures and also by reaction of Na4P2S6 · 6H2O with CsCl in aqueous solution. Both reaction products have closely related vibrational spectra which are assigned on the basis of a P2S64- anion with perturbed D3d symmetry. A normal coordinate analysis has been performed using a force Field with 4 initial force constants. The refined force Field, potential energy distribution (PED), mean amplitudes of vibration and Coriolis coupling constants are given.

Normalkoordinatenanalyse und mittlere Schwingungsamplituden für Cl5SbOPCl3 , Cl5NbOPCl3 und Cl5TaOPCl3

1978 ◽  
Vol 33 (6) ◽  
pp. 709-713 ◽  
Author(s):  
Wolfgang Brockner ◽  
Bjørg N. Cyvin ◽  
Sven J. Cyvin
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Vibrational Frequencies ◽  
Normal Coordinate Analysis ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Symmetry Coordinates ◽  
Initial Force

Abstract A normal coordinate analysis was performed for some Cl5MOPCl3 molecules (M = Sb, Nb, Ta). The final force field in terms of a described set of symmetry coordinates is reported for Cl5SbOPCl3. The initial force field for Cl5SbOPCl3 was applied to calculate the vibrational frequencies of the Cl5NbOPCl3 and Cl5TaOPCl3 adducts. An assignment of the vibrational frequencies of the title compounds and the corresponding potential energy distribution terms are given for Cl5SbOPCl3 . For the Cl5SbOPCl3

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