scholarly journals Symmetry of Terms in the Temperature Factor for Bragg Diffraction of X Rays or Neutrons

1985 ◽  
Vol 38 (3) ◽  
pp. 421
Author(s):  
SL Mair
Keyword(s):  
Point Group ◽  
Waller Factor ◽  
Bragg Diffraction ◽  
Group Symmetry ◽  
X Rays ◽  
Point Group Symmetry ◽  
Many Body ◽  
Crystal Potential ◽  
Debye Waller Factor ◽  
Particle Potential

Terms in the anharmonic Debye-Waller factor, taken as a perturbation about the harmonic case to second order in the van Hove ordering parameter, are classified according to the point-group symmetry of the vibrating atom. The classification is valid for a fully interacting (many-body) crystal potential. It is pointed out that certain terms, which are symmetry-allowed for such a general crystal potential, are excluded if an effective one-particle potential is employed.

Gas Phase Spin Relaxation of ZX3Y Molecules in the Dipolar Approximation

1975 ◽  
Vol 53 (7) ◽  
pp. 723-738 ◽  
Author(s):  
B. C. Sanctuary ◽  
R. F. Snider
Keyword(s):  
Kinetic Theory ◽  
Gas Phase ◽  
Magnetic Relaxation ◽  
Dipolar Coupling ◽  
Point Group ◽  
Group Symmetry ◽  
Subsequent Paper ◽  
Point Group Symmetry ◽  
Proper Treatment ◽  
Gas Kinetic Theory

The gas kinetic theory of nuclear magnetic relaxation of a polyatomic gas, as formulated in the previous paper, is evaluated for ZX3Y molecules relaxing via a dipolar coupling Hamiltonian. Stress is given to a proper treatment of point group symmetry, here C3v, and the possibility of molecular inversion is included. The detailed formula for the spin traces is however restricted to X nuclei with spin 1/2. A subsequent paper uses these results to elucidate the structure of the high density dependence of T1 forCF3H.

scholarly journals Spin-reversal energy barriers of 305 K for Fe2+ d6 ions with linear ligand coordination

Nanoscale ◽  
2017 ◽  
Vol 9 (30) ◽  
pp. 10596-10600 ◽  
Author(s):  
Lei Xu ◽  
Ziba Zangeneh ◽  
Ravi Yadav ◽  
Stanislav Avdoshenko ◽  
Jeroen van den Brink ◽  
...  
Keyword(s):  
Solid State ◽  
Magnetic Anisotropy ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
State Matrix ◽  
Magnetic Anisotropy Energy ◽  
Spin Reversal ◽  
Ligand Coordination ◽  
Li Ion

A remarkably large magnetic anisotropy energy of 305 K is computed by quantum chemistry methods for divalent Fe2+ d6 substitutes at Li-ion sites with D6h point-group symmetry within the solid-state matrix of Li3N.

Tunable double Weyl phonons driven by chiral point group symmetry

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Y. J. Jin ◽  
Z. J. Chen ◽  
X. L. Xiao ◽  
H. Xu
Keyword(s):  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry

scholarly journals Dodecaallylhexasilacyclohexane

IUCrData ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Yoshiyuki Mizuhata ◽  
Yamato Omatsu ◽  
Norihiro Tokitoh
Keyword(s):  
Title Compound ◽  
Point Group ◽  
Chair Conformation ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Compound C

The molecule of the title compound, C36H60Si6, exhibits point group symmetryCi, with the centre of inversion located at the centre of the Si6ring. The Si6ring has a chair conformation. In the crystal, molecules are linkedviaC—H...π(allyl) interactions.

scholarly journals Synthesis, structure determination and characterization by UV–Vis and IR spectroscopy of bis(diisopropylammonium) cis-dichloridobis(oxalato-κ2 O 1,O 2)stannate(IV)

2019 ◽  
Vol 75 (6) ◽  
pp. 742-745
Author(s):  
Bougar Sarr ◽  
Abdou Mbaye ◽  
Cheikh Abdoul Khadir Diop ◽  
Mamadou Sidibe ◽  
Yoann Rousselin
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Point Group ◽  
Chain Structure ◽  
Chloride Ions ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Chloride Dihydrate ◽  
Distorted Octahedral Coordination ◽  
Distorted Octahedral

The organic–inorganic title salt, (C6H16N)2[Sn(C2O4)2Cl2] or ( i Pr2NH2)2[Sn(C2O4)2Cl2], was obtained by reacting bis(diisopropylammonium) oxalate with tin(IV) chloride dihydrate in methanol. The SnIV atom is coordinated by two chelating oxalate ligands and two chloride ions in cis positions, giving rise to an [Sn(C2O4)2Cl2]2− anion (point group symmetry 2), with the SnIV atom in a slightly distorted octahedral coordination. The cohesion of the crystal structure is ensured by the formation of N—H...O hydrogen bonding between (iPr2NH2)+ cations and [SnCl2(C2O4)2]2− anions. This gives rise to an infinite chain structure extending parallel to [101]. The main inter-chain interactions are van der Waals forces. The electronic spectrum of the title compound displays only one high intensity band in the UV region assignable to ligand–metal ion charge-transfer (LMCT) transitions. An IR spectrum was also recorded and is discussed.

Pseudo-symmetry in multiple twinned crystals having M3M point group symmetry

1971 ◽  
Vol 2 (12) ◽  
pp. 3485-3486 ◽  
Author(s):  
Santiago Harriague ◽  
Harry A. Leibovich
Keyword(s):  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry
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