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.

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.

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.

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 Some Nitrogen-Halogen Compounds

1970 ◽  
Vol 25 (2) ◽  
pp. 169-173 ◽  
Author(s):  
K. Ramaswamy ◽  
N. Mohan
Keyword(s):  
Potential Energy ◽  
Linear Relationship ◽  
Force Constant ◽  
Bond Order ◽  
Normal Coordinate Analysis ◽  
Normal Coordinate ◽  
Molecular Constants ◽  
Halogen Compounds ◽  
Bond Stretching ◽  
Energy Constants

The approximate force fields for a group of nitrogen halogen compounds like ONF3, NF3, NF2Cl, NFCl2, NF2D and NCl3 were studied using the kinematic methods of Herranz and Torkington. It was found that the application of Torkington's method yields a reliable set of potential energy constants consistent with other molecular constants. A linear relationship between the N -F bond stretching force constants and the bond order was found to exist. It was also found that the value of the N-F bond stretching force constant is proportional to the number of fluorine atoms substituted.

Détermination des constantes de force et des amplitudes moyennes de vibration du sous-sulfure de carbone, C3S2

1968 ◽  
Vol 46 (16) ◽  
pp. 2641-2643 ◽  
Author(s):  
Alpha O. Diallo
Keyword(s):  
Vibrational Frequencies ◽  
Force Constants ◽  
Mean Square ◽  
Mean Amplitudes Of Vibration ◽  
Symmetrical Structure ◽  
Symmetry Coordinates ◽  
Shrinkage Effect ◽  
The Mean ◽  
Generalized Mean

The theory of the generalized mean amplitudes of vibration has been applied to the C3S2 molecule, which possesses a linear symmetrical structure. The numerical values of the force constants and the mean square parallel and perpendicular amplitudes at 298°K of all bonded and non-bonded pairs of atoms are calculated from spectroscopic vibrational frequencies by the Cyvin and Morino–Hirota methods, utilizing the symmetry coordinates. The "shrinkage" effect constants are also evaluated by means of the perpendicular mean square amplitudes.

Bond properties of anionic mixed halogeno-complexes InX3Y- (X ≠ Y = Cl, Br, I)

1985 ◽  
Vol 50 (2) ◽  
pp. 329-335 ◽  
Author(s):  
D. R. Singh ◽  
U. P. Verma ◽  
A. N. P. Pandey ◽  
Bohuslav Strauch
Keyword(s):  
Bond Order ◽  
Reliable Data ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Bond Properties ◽  
Normal Coordinate ◽  
Fundamental Frequencies ◽  
Bond Polarizability ◽  
The Mean

The normal coordinate analysis has been performed for the anionic mixed halogeno-complexes InX3Y- (X ≠ Y = Cl, Br, I). The trends among the force constants are discussed and the assignments of the observed fundamental frequencies are examined thoroughly. It has been found that the present analysis provides reliable data to introduce a light into the bond properties of InX3Y- ions. In addition to this the mean amplitudes of vibrations, bond order and bond polarizability derivatives have been studied for the systems under investigation and a comparison of bond parameters among the halides of indium are made.

Normal Coordinate Analysis and Mean Amplitudes of Vibration of Spiropentane

1974 ◽  
Vol 29 (12) ◽  
pp. 1898-1901 ◽  
Author(s):  
B. N. Cyvin ◽  
O. Gebhardt
Keyword(s):  
Electron Diffraction ◽  
Potential Energy ◽  
Spectroscopic Data ◽  
Field Potential ◽  
Normal Coordinate Analysis ◽  
Potential Energy Distribution ◽  
Structure Parameters ◽  
Harmonic Force ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration

Using spectroscopic data and structure parameters observed by electron diffraction, a normal coordinate analysis was performed for spiropentane. Harmonic force field, potential energy distribution and calculated mean amplitudes of vibration are reported. A very satisfactory agreement is found between observed and calculated mean amplitudes of vibration.

scholarly journals Zur Berechnung von mittleren Schwingungsamplituden

1968 ◽  
Vol 23 (7) ◽  
pp. 1024-1028
Author(s):  
A. Müller ◽  
B. Krebs ◽  
C. J. Peacock
Keyword(s):  
Approximation Method ◽  
Simple Formula ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Matrix Approximation ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Atomic Masses

Some rules for mean amplitudes of vibration u are given. It is shown that the u values for bonded atoms can be calculated by a simple formula needing only stretching force constants and atomic masses. The values obtained for a number of XY3(C3v) and XY4(Td) molecules show generally less than 5% difference from the rigorously calculated ones. The data published in the literature are often several times too large. For the XY3(C3v) molecules a normal coordinate analysis in a M.V.F.F. approximation is given. From a new simple L matrix approximation method mean amplitudes of vibration have been calculated for these species which also agree very well with rigorously calculated ones.

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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