Crystallographic symmetry point group notation flow chart

1987 ◽  
Vol 64 (3) ◽  
pp. 216 ◽  
Author(s):  
G. L. Breneman
Keyword(s):  
Point Group ◽  
Flow Chart ◽  
Symmetry Point ◽  
Symmetry Point Group ◽  
Crystallographic Symmetry

scholarly journals New computer program to calculate the symmetry of molecules

2005 ◽  
Vol 3 (4) ◽  
pp. 647-657 ◽  
Author(s):  
Ali Ashrafi ◽  
Mohammad Ahmadi
Keyword(s):  
Automorphism Group ◽  
Computer Program ◽  
Cyclic Group ◽  
Point Group ◽  
Alternating Group ◽  
Symmetry Point ◽  
Symmetry Point Group ◽  
Symmetry Of Molecules

AbstractIn this paper we, present some MATLAB and GAP programs and use them to find the automorphism group of the Euclidean graph of the C80 fullerence with connectivity and geometry of Ih symmetry point group. It is proved that this group has order 120 and is isomorphic to Ih≊Z2×A5, where Z2 is, a cyclic group of order 2 and A5 is the alternating group on five symbols.

Symmetry point group description of second harmonic generation in carbon nanotubes

2004 ◽  
Vol 1 (4) ◽  
pp. 172-175 ◽  
Author(s):  
L De Dominicis ◽  
R Fantoni ◽  
S Botti ◽  
L S Asilyan ◽  
R Ciardi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Point Group ◽  
Symmetry Point ◽  
Symmetry Point Group

scholarly journals Di-μ-hydroxido-κ4O:O-di-μ-perchlorato-κ4O:O′-bis[(2,2′-bipyridine-κ2N,N′)copper(II)]

2013 ◽  
Vol 69 (11) ◽  
pp. m600-m600 ◽  
Author(s):  
B. Saravanan ◽  
A. Jayamani ◽  
N. Sengottuvelan ◽  
G. Chakkaravarthi ◽  
V. Manivannan
Keyword(s):  
Rotation Axis ◽  
Point Group ◽  
Mirror Plane ◽  
Distorted Octahedral Geometry ◽  
Binuclear Copper ◽  
Symmetry Point ◽  
Symmetry Point Group ◽  
Centroid Distance ◽  
Distorted Octahedral ◽  
Jahn Teller

In the title binuclear copper(II) complex, [Cu2(ClO4)2(OH)2(C10H8N2)2], the CuIIion is coordinated in the form of a Jahn–Teller distorted octahedron by two bipyridine N atoms, two perchlorate O atoms and two hydroxide O atoms, and displays a distorted octahedral geometry. The molecule belongs to the symmetry point groupC2h. The CuIIion is located on a twofold rotation axis and the hydroxide and perchlorate ligands are located on a mirror plane. Within the dinuclear molecule, the Cu...Cu separation is 2.8614 (7) Å. The crystal structure exhibits O—H...O, C—H...O and π–π [centroid–centroid distance = 3.5374 (13) Å] interactions.

Potential Constants and Thermodynamic Properties of Iodine Pentafluoride

1962 ◽  
Vol 17 (10) ◽  
pp. 871-874
Author(s):  
G. Nagarajan
Keyword(s):  
Heat Capacity ◽  
Point Group ◽  
Heat Content ◽  
Symmetry Point ◽  
Symmetry Point Group ◽  
Rigid Rotator ◽  
Fundamental Frequencies ◽  
Symmetry Coordinates ◽  
Tetragonal Pyramidal ◽  
Harmonic Oscillator Approximation

An orthonormalized set of symmetry coordinates satisfying the transformation properties has been constructed for the iodine pentafluoride molecule having the tetragonal pyramidal structure with the symmetry point group C4v. Utilising these symmetry coordinates and a potential function consisting of the ordinary valence force terms and central force terms, the elements of potential and kinetic energy matrices have been obtained. From the observed RAMAN and infrared fundamental frequencies the potential constants and thermodynamics properties such as heat content, free energy, entropy and heat capacity have been calculated for a rigid rotator, harmonic oscillator approximation.

Niobocene Dichloride and Niobocene Diiodide: Electronic Absorption Spectra and Electron Spin Resonance

1998 ◽  
Vol 63 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Point Group ◽  
Esr Spectra ◽  
Ligand Field ◽  
Orbital Interaction ◽  
Symmetry Point Group ◽  
Spin Orbital ◽  
Halide Ligands

The effect of the halide ligand on the bonding of niobium in niobocene dichloride and niobocene diiodide was investigated. The electronic absorption spectra of the two compounds in the range of d-d transitions were resolved into four bands corresponding to transitions of the d1 electron between five frontier orbitals in a molecule of symmetry point group C2v. The energies of the frontier molecular orbitals were determined relatively to the energy of the orbitals in the spherically symmetric ligand field formed by the appropriate halide ligands. The effect of the halide ligands on the spin-orbital interaction of the HOMO orbital is discussed qualitatively on the basis the ESR spectra.

scholarly journals Comparison study of CC and CH vibration frequencies and eelectronic properties for mono, Di, Tri, and tetra-rings layer of arm chair (SWCNTs)

2019 ◽  
Vol 11 (20) ◽  
pp. 85-99
Author(s):  
Huda N. Al-Ani
Keyword(s):  
Point Group ◽  
Ir Absorption ◽  
Vibration Frequencies ◽  
Comparison Study ◽  
Symmetry Point Group ◽  
Bending Vibrations ◽  
Modes Of Vibration ◽  
Program Comparison ◽  
Semi Empirical ◽  
Equilibrium Geometries

Semi-empirical methods were applied for calculating the vibration frequencies and IR absorption intensities for normal coordinates of the {mono (C56H28), di (C84H28), tri (C112H28) and tetra (C140H28)} -rings layer for (7,7) armchair single wall carbon nanotube at their equilibrium geometries which were all found to have D7d symmetry point group. Assignment of the modes of vibration (3N-6) was done depending on the pictures of their modes by applying (Gaussian 03) program. Comparison of the vibration frequencies of (mono, di, tri and tetra) rings layer which are active in IR, and inactive in Ramman spectra. For C-H stretching vibrations, the results showed that vibration frequencies value increased with increased of length nano tube (rings layer SWCNT). The results include the relation for axial bonds, which are the vertical C-C bonds (annular bonds) in the rings and for circumferential bonds which are the outer ring bonds. Also include the assignment of puckering, breathing and clock-anticlockwise bending vibrations. They allow a comparative view of the charge density at the carbon atom too.

X-Ray Diffraction

2021 ◽  
pp. 408-480
Author(s):  
Kannan M. Krishnan
Keyword(s):  
Point Group ◽  
Polycrystalline Materials ◽  
X Rays ◽  
X Ray Diffraction ◽  
Symmetry Point Group ◽  
X Ray ◽  
Atomic Scattering ◽  
Scattering Factor ◽  
Diffraction Patterns ◽  
Lattice Planes

X-rays diffraction is fundamental to understanding the structure and crystallography of biological, geological, or technological materials. X-rays scatter predominantly by the electrons in solids, and have an elastic (coherent, Thompson) and an inelastic (incoherent, Compton) component. The atomic scattering factor is largest (= Z) for forward scattering, and decreases with increasing scattering angle and decreasing wavelength. The amplitude of the diffracted wave is the structure factor, F hkl, and its square gives the intensity. In practice, intensities are modified by temperature (Debye-Waller), absorption, Lorentz-polarization, and the multiplicity of the lattice planes involved in diffraction. Diffraction patterns reflect the symmetry (point group) of the crystal; however, they are centrosymmetric (Friedel law) even if the crystal is not. Systematic absences of reflections in diffraction result from glide planes and screw axes. In polycrystalline materials, the diffracted beam is affected by the lattice strain or grain size (Scherrer equation). Diffraction conditions (Bragg Law) for a given lattice spacing can be satisfied by varying θ or λ — for study of single crystals θ is fixed and λ is varied (Laue), or λ is fixed and θ varied to study powders (Debye-Scherrer), polycrystalline materials (diffractometry), and thin films (reflectivity). X-ray diffraction is widely applied.

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