Vibrational spectra of arsenic triiodide

1968 ◽  
Vol 21 (10) ◽  
pp. 2379 ◽  
Author(s):  
MA Hooper ◽  
DW James
Keyword(s):  
Raman Spectrum ◽  
Solid State ◽  
Vibrational Spectra ◽  
Point Group ◽  
Group Symmetry ◽  
Space Group Symmetry ◽  
Space Group ◽  
Polarization Studies

The Raman spectrum of AsI3 has been determined in solution in CS2 and in the solid state. For the solution the assignment of Stammreich, Forneris, and Tavares has been confirmed by polarization studies. In the solid state it is shown that assignment of the spectrum is only possible on the basis of space group symmetry and an earlier assignment based on point group C3v is in error. The solid state frequencies (R3 symmetry) are v1(Ag) 185 cm-l, v2(Ag) 75 cm-l, v3(Au) 201 cm-l, v4(Au) 102 cm-1, v5(Eg) 205 cm-1, v6(Eg) 50 cm-l, v7(Eg) 216 cm-1, v8(Eg) 74 cm-1.

Manifestations of latent space group symmetry in the vibrational spectra of MSO4; where M=Ba, Sr, and Pb

1991 ◽  
Vol 94 (9) ◽  
pp. 5946-5948 ◽  
Author(s):  
Upali A. Jayasooriya ◽  
Sidney F. A. Kettle ◽  
Sujit Mahasuverachai ◽  
Osama Al‐Jowder
Keyword(s):  
Vibrational Spectra ◽  
Group Symmetry ◽  
Space Group Symmetry ◽  
Space Group ◽  
Latent Space

scholarly journals CSDSymmetry: a database of point group and space group symmetry relationships in crystal structures

2002 ◽  
Vol 58 (s1) ◽  
pp. c367-c367
Author(s):  
W. D. S. Motherwell ◽  
E. Pidcock ◽  
J. W. Yao ◽  
J. C. Cole ◽  
F. H. Allen ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Point Group ◽  
Group Symmetry ◽  
Space Group Symmetry ◽  
Space Group

scholarly journals Classification and Effects of Symmetry of Mechanical Structure and its Application in Design

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 683
Author(s):  
Qingying Qiu ◽  
Xiuming Chen ◽  
Chao Yang ◽  
Peien Feng
Keyword(s):  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Space Group Symmetry ◽  
Space Group ◽  
Mechanical Structure ◽  
Natural Objects ◽  
Mechanical Products ◽  
Speed Change ◽  
And Performance

Symmetry widely exists in natural objects and man-made objects. Mechanical structures, as man-made objects, have the property of symmetry without exception. The existence of symmetry affects the function and performance of mechanical products. Therefore, on the basis of analyzing a large number of examples and referring to the Schoenflies symbol of crystal, the symmetry of mechanical structures is divided into point group symmetry and space group symmetry, and these two types are further subdivided according to the types and spatial positions of the symmetry elements. Then, the general effects of symmetry are summarized according to symmetry types and functions, and several symmetry rules for design are further refined. Finally, after defining the requirements of speed change and technology background, a multispeed device for bicycle shaft drive is proposed by applying symmetry knowledge comprehensively.

The atomic anisotropic displacement tensor – completing the picture

2015 ◽  
Vol 71 (4) ◽  
pp. 467-470 ◽  
Author(s):  
Gunnar Thorkildsen ◽  
Helge B. Larsen
Keyword(s):  
Point Group ◽  
Transformation Property ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Tensor Representation ◽  
Space Group Symmetry ◽  
Space Group ◽  
Simplified Approach ◽  
Displacement Parameter ◽  
Isotropic Displacement Parameter

A simplified approach for calculating the equivalent isotropic displacement parameter is presented and the transformation property of the tensor representationUto point-group operations is analysed. Complete tables have been compiled for the restrictions imposed upon the tensor owing to the site symmetry associated with all special positions as listed in Hahn [(2011),International Tables for Crystallography, Vol. A,Space-group Symmetry, 5th revised ed. Chichester: John Wiley and Sons, Ltd].

Hydrothermal Synthesis and Solid-State Laser Refrigeration of Ytterbium-Doped Potassium Lutetium Fluoride (KLF) Microcrystals

2020 ◽  
Author(s):  
Xiaojing Xia ◽  
Anupum Pant ◽  
Xuezhe Zhou ◽  
Elena Dobretsova ◽  
Alex Bard ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Solid State ◽  
Information Science ◽  
Point Group ◽  
Solid State Laser ◽  
Lanthanide Ions ◽  
Group Symmetry ◽  
Luminescence Spectra ◽  
Crystalline Phases ◽  
State Laser

Fluoride crystals, due to their low phonon energies, are attractive hosts of trivalent lanthanide ions for applications in upconverting phosphors, quantum information science, and solid-state laser refrigeration. In this article, we report the rapid, low-cost hydrothermal synthesis of potassium lutetium fluoride (KLF) microcrystals for applications in solid-state laser refrigeration. Four crystalline phases were synthesized, namely orthorhombic K<sub>2</sub>LuF<sub>5</sub> (Pnma), trigonal KLuF<sub>4</sub> (P3<sub>1</sub>21), orthorhombic KLu<sub>2</sub>F<sub>7</sub> (Pna2<sub>1</sub>), and cubic KLu<sub>3</sub>F<sub>10</sub> (Fm3m), with each phase exhibiting unique microcrystalline morphologies. Luminescence spectra and emission lifetimes of the four crystalline phases were characterized based on the point-group symmetry of trivalent cations. Laser refrigeration was measured by observing both the optomechanical eigenfrequencies of microcrystals on cantilevers in vacuum, and also the Brownian dynamics of optically trapped microcrystals in water. Among all four crystalline phases, the most significant cooling was observed for 10%Yb:KLuF<sub>4</sub> with cooling of 8.6 $\pm$ 2.1 K below room temperature. Reduced heating was observed with 10%Yb:K<sub>2</sub>LuF<sub>5</sub>

scholarly journals Multiplicity, Parity and Angular Momentum of a Cooper Pair in Unconventional Superconductors of D4h Symmetry: Sr2RuO4 and Fe-Pnictide Materials

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1435
Author(s):  
Victor G. Yarzhemsky
Keyword(s):  
Angular Momentum ◽  
Cooper Pair ◽  
Point Group ◽  
Group Symmetry ◽  
Cooper Pairs ◽  
Group Approach ◽  
Angular Momentum Projection ◽  
Space Group ◽  
Unconventional Superconductors ◽  
Even Pairs

Sr2RuO4 and Fe-pnictide superconductors belong to the same point group symmetry D4h. Many experimental data confirm odd pairs in Sr2RuO4 and even pairs in Fe-pnictides, but opposite conclusions also exist. Recent NMR results of Pustogow et al., which revealed even Cooper pairs in Sr2RuO4, require reconsideration of symmetry treatment of its SOP (superconducting order parameter). In the present work making use of the Mackey–Bradley theorem on symmetrized squares, a group theoretical investigation of possible pairing states in D4h symmetry is performed. It is obtained for I4/mmm , i.e., space group of Sr2RuO4, that triplet pairs with even spatial parts are possible in kz direction and in points M and Y. For the two latter cases pairing of equivalent electrons with nonzero total momentum is proposed. In P4/nmm space group of Fe- pnictides in point M, even and odd pairs are possible for singlet and triplet cases. It it shown that even and odd chiral states with angular momentum projection m=±1 have nodes in vertical planes, but Eg is nodal , whereas Eu is nodeless in the basal plane. It is also shown that the widely accepted assertion that the parity of angular momentum value is directly connected with the spatial parity of a pair is not valid in a space-group approach to the wavefunction of a Cooper pair.

Raman-Spektren von SnJ4, GeJ4, TiBr4 und TiJ4 in flüssiger und kristalliner Phase / Raman Spectra of SnJ4, GeJ4, TiBr4, and TiJ4 in the Liquid and Crystalline Phase

1970 ◽  
Vol 25 (12) ◽  
pp. 1374-1381 ◽  
Author(s):  
W. Kiefer ◽  
H. W. Schrötter
Keyword(s):  
Raman Spectra ◽  
Ruby Laser ◽  
Detection System ◽  
Point Group ◽  
Visible Region ◽  
Group Symmetry ◽  
Pure Liquid ◽  
Electronic Detection ◽  
Polarization Studies ◽  
First Time

The Raman spectra of four molecules absorbing in the visible region (SnJ4, GeJ4, TiBr4, and TiJ4) are presented. They were excited with a quasi-continuous ruby laser and recorded with a special electronic detection system. Except for TiJ4, complete Raman spectra of crystal powder pellets could be obtained for the first time. The assignment reported by previous authors was confirmed by accurate polarization studies of solutions or pure liquid. The assignment is also in the solid state possible on the basis of Td point group symmetry. The fundamental vibrations of TiJ4 in solutions are: ν1 (A1) =162, ν2 (E) =51, ν3 (F2) =319 and ν4 (F2) Y = 67 cm-1

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