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.

Molecular Vibration Analysis of the TeCl4 Tetramer and Monomer and the SeCl4 Tetramer

1978 ◽  
Vol 33 (6) ◽  
pp. 714-721 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
W. Brockner ◽  
A. F. Demiray
Keyword(s):  
Potential Energy ◽  
Vibration Analysis ◽  
Force Fields ◽  
Molecular Vibration ◽  
Potential Energy Distribution ◽  
Monomeric Form ◽  
Frequency Shifts ◽  
Mean Amplitudes Of Vibration ◽  
Symmetry Coordinates ◽  
Tetrahedral Complexes

Abstract The molecular vibrations of (TeCl4)4 and (SeCl4)4 are studied on the basis of a cubane-like Td model. Symmetry coordinates are produced by using the theory developed for tetrahedral complexes with trigonal ligands. Approximate vibrational frequencies are calculated from very simple four-parameter force fields and used as an aid in tentative assignments of observed frequencies from literature. Next the force fields are refined by adjustments to the observed frequencies assigned as fundamentals. Potential energy distribution terms and mean amplitudes of vibration are calculated. Finally the monomeric form of TeCl4 is analysed, mainly in order to show the frequency shifts on passing from the monomer to tetramer.

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.

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 .

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 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.

Normal coordinate analysis of cyanoacetylene

1968 ◽  
Vol 21 (3) ◽  
pp. 575 ◽  
Author(s):  
K Ramaswamy ◽  
K Srinivasan
Keyword(s):  
Potential Energy ◽  
Force Fields ◽  
Pair Bond ◽  
Normal Coordinate Analysis ◽  
Characteristic Set ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Bond Pair ◽  
The Mean ◽  
Energy Constants

The potential energy constants of cyanoacetylene were obtained by the method of characteristic set. The values of the various bond pair-bond pair interactions were determined without any assumptions regarding force fields. The mean amplitudes of vibration for the various characteristic bonds were calculated by Cyvin's method. The results are explained on the basis of the presence of conjugated structures for cyanocetylene.

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.

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