Schwingungsberechnungen der käfigstrukturierten Moleküle α–P4S4, As4S4 und As4Se4

1988 ◽  
Vol 43 (4) ◽  
pp. 326-330
Author(s):  
L. Ohse ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Spectroscopic Data ◽  
Field Potential ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration ◽  
Standard Thermodynamic Functions ◽  
Initial Force

Abstract A normal coordinate analysis for the cage-like molecules α-P4S4, As4S4 and As4Se4 is performed, based on a simple initial force field with three numerical parameters and valence coordinates including redundancies. The force field is refined by adjusting the symmetry force constants to fit the observed frequencies. The final force field, potential energy distribution (PED), mean amplitudes of vibration and the standard thermodynamic functions from spectroscopic data are also given for the title compounds.

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.

Schwingungsspektren und Normalkoordinatenanalyse des P2Se64–-Anions in den konformeren staggered- und eclipsed-Anordnungen in TL4P2Se6und Na4P2Se6

1986 ◽  
Vol 41 (10) ◽  
pp. 1233-1237 ◽  
Author(s):  
M. Parensen ◽  
W. Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Vibrational Spectroscopy ◽  
Field Potential ◽  
Coupling Constants ◽  
Potential Energy Distribution ◽  
Coriolis Coupling ◽  
Normal Coordinate ◽  
Mean Amplitudes Of Vibration

Na4P2Se6 has been prepared by elemental synthesis at high temperatures and characterized by vibrational spectroscopy. The vibrational frequencies of Na4P2Se6 are assigned on the basis of eclipsed P2Se64- conformers with D3h symmetry, those of Tl4P2Se6 on the basis of staggered P2Se64- units with D3d symmetry. A normal coordinate analysis has been performed for both conformers. The refined force field, potential energy distribution (PED), mean amplitudes of vibration an Coriolis coupling constants are given.

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 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

The Vibrational Spectrum and Urey-Bradley Force Constants of the Trifluoromethyltrifluoroborate(1-) Anion

1973 ◽  
Vol 27 (3) ◽  
pp. 209-213 ◽  
Author(s):  
John F. Jackovitz ◽  
Charles E. Falletta ◽  
James C. Carter
Keyword(s):  
Potential Energy ◽  
Vibrational Spectrum ◽  
Energy Distribution ◽  
Force Field ◽  
Raman Spectra ◽  
Normal Modes ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate

Infrared and Raman spectra for (K+) (CF3BF3−) have been obtained from 4000 to 50 cm−1. Spectral assignments were made on the basis of C3v symmetry using both 10B and 11B compounds. In addition, a normal coordinate analysis was performed to obtain the potential energy distribution of the normal modes. A Urey-Bradley type force field was used, and force constants obtained for the CF3 and BF3 groupings were compared to those in C2F6 and BF4−.

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.

Vibrations of a Cage-like Molecule, P4S3: Some Theoretical Aspects

1981 ◽  
Vol 36 (7) ◽  
pp. 774-777 ◽  
Author(s):  
S. J. Cyvin ◽  
B. N. Cyvin ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Potential Energy ◽  
Energy Distribution ◽  
Force Field ◽  
Normal Modes ◽  
Potential Energy Distribution ◽  
Symmetry Coordinates ◽  
Method Of Fragments ◽  
Compliance Matrices

Abstract Two independent symmetry coordinate sets for P4S3 are developed, starting from the "method of fragments". A simple, approximate force field is expressed in terms of the two sets of symmetry coordinates, and the corresponding compliance matrices are given. The invariance of compliants is demonstrated. The potential energy distribution (PED) is discussed. An example is shown where the PED terms are clearly inadequate for the description of normal modes. A general warning against the interpretation of the PED in terms of such descriptions for cage-like structures seems to be warranted. V ib r a tio n s o f a C a g e -lik e M o le c u le , P 4S3 : S o m e T h e o r e tic a l A sp e c ts

Schwingungsspektren und Normalkoordinatenanalyse der isotopomeren closo-Hexaiodohexaborate 11Bn10B6-nI62-, n = 0 - 6

1991 ◽  
Vol 46 (1) ◽  
pp. 19-24 ◽  
Author(s):  
J. Thesing ◽  
W. Preetz ◽  
J. Baurmeister
Keyword(s):  
Solid State ◽  
Potential Energy ◽  
Energy Distribution ◽  
Potential Energy Distribution ◽  
Site Symmetry ◽  
Geometric Isomers ◽  
Normal Coordinate ◽  
Valence Force Field ◽  
Atomic Displacements ◽  
Good Agreement

Normal coordinate analyses for the ten isotopomers Cs211Bn10B6-nI6, n = 0 - 6 , including the pairs of geometric isomers for n = 2, 3, 4 have been performed, based on a general valence force field. Using a set o f 8 force constants (e.g. fd(BB) = 1.45, fd(BI) = 2.33 mdyn/Å ) the calculated frequencies are in good agreement with observed IR and R am an bands measured at 10 or 80 K for Cs2B6I6 with natural abundance of B isotopes (~80% 11B , 20% 10B) as well as for 11B and 10B enriched derivatives. From the calculated atomic displacements and the potential energy distribution the classification in the 30 times more intense substituent (in-phase motions of B and I, ≤ 153 cm-1) and the weak cage vibrations (anti-phase displacements of B and I, ≥ 385 cm-1) is deduced. Only the cage modes show characteristic band patterns, explained by the superposition of the calculated spectra of the different isotopomers in accordance with their statistical abundance. There is an excellent conformity for the total symmetric A, vibration, but for the triply degenerate T lu and T 2g modes as a consequence of lowered site symmetry in the solid state more bands than calculated are observed.

Sign in / Sign up

Export Citation Format

Share Document