scholarly journals Unit Cell Group and the Factor Group in the Theory of the Electronic and Vibrational Spectra of Crystals

1971 ◽  
Vol 54 (1) ◽  
pp. 160-162 ◽  
Author(s):  
J. E. Bertie ◽  
J. W. Bell
Keyword(s):  
Vibrational Spectra ◽  
Factor Group ◽  
Unit Cell ◽  
Cell Group ◽  
Electronic And Vibrational Spectra

Vibrational spectra and normal coordinate analysis of crystallinelithium metasilicate

1977 ◽  
Vol 55 (13) ◽  
pp. 2559-2563 ◽  
Author(s):  
V. Devarajan ◽  
H. F. Shurvell
Keyword(s):  
Vibrational Spectra ◽  
Unit Cell ◽  
Normal Coordinate Analysis ◽  
Cell Group ◽  
Vibrational Modes ◽  
Infrared And Raman Spectra ◽  
Vibrational Assignment ◽  
Normal Coordinate ◽  
Lithium Metasilicate ◽  
Symmetry Species

Infrared and Raman spectra of polycrystalline lithium metasilicate have been recorded. A vibrational assignment in terms of the various symmetry species of the unit cell group, C2v, has been made. A normal coordinate analysis of the unit cell vibrations at the centre of the Brillouin zone (k = 0) was carried out to support the assignment and provide descriptions of the vibrational modes. The results are discussed in the light of previous normal coordinate calculations on the isolated metasilicate chain.

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

Nitroethane at high density: an experimental and computational vibrational study

2021 ◽  
Vol 23 (15) ◽  
pp. 9325-9336
Author(s):  
Akio Yoshinaka ◽  
Serge Desgreniers ◽  
Anguang Hu
Keyword(s):  
High Pressure ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Unit Cell ◽  
High Density ◽  
Monoclinic Unit Cell ◽  
Vibrational Study

Raman and IR vibrational spectra confirm two molecular units associated with the monoclinic unit cell of nitroethane under high pressure. Raman spectra are extremely sensitive to predicted effects of unit cell distortion due to changes in H-bonding.

Synthesis, crystal and molecular structure, and vibrational spectra of the complex (COOH)2•2H2O•18-crown-6

1986 ◽  
Vol 64 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Suzanne Deguire ◽  
François Brisse ◽  
Jacques Ouellet ◽  
Rodrigue Savoie
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Oxalic Acid ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Infrared And Raman Spectra ◽  
O 18 ◽  
Stoichiometric Complex

A stoichiometric complex of formula (COOH)2•2H2O•18-crown-6 has been obtained from oxalic acid and the macrocyclic polyether 18-crown-6. The crystals of the complex have a monoclinic unit cell and belong to the P21/c space group. The components in the adduct are linked through hydrogen bonds in a polymer-like fashion: -crown–H2O–HOOCCOOH–OH2–crown–, where the oxalic acid molecules are present in two distinct disordered orientations. The infrared and Raman spectra of the complex are also reported and interpreted.

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