Theoretical studies of the local structure and EPR parameters for Cu2+ centers in disodium malonate trihydrate single crystal

2015 ◽  
Vol 456 ◽  
pp. 125-128 ◽  
Author(s):  
Li Chao-Ying ◽  
Huang Ying ◽  
Zheng Xue-Mei
Keyword(s):  
Single Crystal ◽  
Local Structure ◽  
Theoretical Studies ◽  
Epr Parameters

Theoretical Studies of the Local Structures and EPR Parameters for the Rhombic Cu2+ Center in Cu0.5Zr2(PO4)3 Phosphate

2015 ◽  
Vol 70 (7) ◽  
pp. 553-557
Author(s):  
Li Chao-Ying ◽  
Huang Ying ◽  
Tu Qiu
Keyword(s):  
Local Structure ◽  
Bond Angle ◽  
Theoretical Studies ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Electron Paramagnetic ◽  
Distortion Angle ◽  
Good Agreement

AbstractThe local structure of the rhombic Cu2+ center in Cu0.5Zr2(PO4)3 phosphate is investigated by using the high-order perturbation formulas of electron paramagnetic resonance (EPR) parameters, g-factors gi (i=x, y, z), and hyperfine structure constants Ai for 3d9 ions in rhombically elongated octahedral symmetry. According to the studies, the local axial distortion angle Δα (≈ 5.1°) and the planar bond angle θ (≈ 83.8°) in [CuO6]10- cluster was obtained. The theoretical EPR parameters based on the aforementioned local structure parameters show good agreement with the observed values, and some improvement have been made as compared with the previous studies.

scholarly journals Theoretical Studies of the EPR Parameters and the Local Structure of the Tetragonal Fe+ Center in KTaO3

2005 ◽  
Vol 60 (1-2) ◽  
pp. 101-105
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong ◽  
Xiu-Ying Gao
Keyword(s):  
Local Structure ◽  
Impurity Center ◽  
Tetragonal Distortion ◽  
Zero Field ◽  
Theoretical Studies ◽  
Zero Field Splitting ◽  
Quadrupole Shift ◽  
Epr Parameters ◽  
Nuclear Quadrupole ◽  
G Factors

The EPR parameters (zero-field splitting D and g factors g‖ and g⊥) and the local structure for the tetragonal Fe+ center in KTaO3 are theoretically studied by using the perturbation formulas of the EPR parameters for a 3d7 ion in tetragonally distorted dodecahedra. Based on these studies, we find that the impurity Fe+ may not locate on the regular dodecahedral K+ site but suffer a large off-center displacement ΔZ (≈ 0.43 Å) along one of the 100 〈or C4〉 axes, which is responsible for the large tetragonal distortion of the impurity center. The displacement ΔZ obtained in this work is comparable with that (≈ 0.46 Å ) of a similar monovalent Li+ on K+ site of KTaO3 obtained from the nuclear quadrupole shift and can be regarded as reasonable. The calculated g factors, particularly the anisotropy Δg (= Kg⊥ −g‖) based on the above displacement, agree with the observed values.

scholarly journals Single-crystal neutron diffraction study of β-Cs3(HSO4)2[H2−x (S x P1−x )O4] (x ≃ 0.5) at 15 K

1999 ◽  
Vol 55 (3) ◽  
pp. 285-296 ◽  
Author(s):  
S. M. Haile ◽  
W. T. Klooster
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Local Structure ◽  
Unit Cell Volume ◽  
Structural Models ◽  
Neutron Diffraction Study ◽  
Unit Cell ◽  
Asymmetric Unit ◽  
X Ray ◽  
Anisotropic Displacement Parameters

The structure of β-Cs3(HSO4)2[H2−x (S x P1−x )O4] has been examined by single-crystal neutron diffraction at 15 K. The compound crystallizes in space group C2/c and contains four formula units in the unit cell, with lattice parameters a = 19.769 (9), b = 7.685 (2), c = 8.858 (3) Å and β = 100.60 (4)°. Refinement of P, S and H site occupancies indicated that the value of x (in the stoichiometry) is 0.500 (6). This, together with the unit-cell volume of 1322.8 (14) Å3, implies a density of 3.463 Mg m−3. The structure contains zigzag rows of XO4 anions, where X = P or S, that alternate, in a checkerboard fashion, with zigzag rows of Cs cations. Moreover, there is one proton site, H(3), with an occupancy of 0.25 and one X-atom site, X(1), that is occupied by 0.5 P and 0.5 S. These features are in general agreement with a previous X-ray structure determination carried out at 298 K. In contrast to the X-ray study, however, it was found that two different structural models adequately fit the diffraction data. In the first model, the proton vacancies and the P atoms were assumed to be randomly distributed over the H(3) and X(1) sites, respectively, and to have no impact on the local structure. In the second model, several atoms were assigned split occupancies over two neighboring sites, to reflect the presence or absence of a proton vacancy, and the presence of P or S on the X(1) site. Refinement assuming the first model, in which anisotropic displacement parameters for 12 of 14 atom sites in the asymmetric unit were employed, yielded residuals w R(F 2) = 0.084 and w R(F) = 0.038. For the second model, in which anisotropic displacement parameters were utilized for only the five atoms that were not split relative to the first model, the residuals were w R(F 2) = 0.081 and w R(F) = 0.036.

Theoretical studies of the local structure and spin Hamiltonian parameters for Rh2+:ZnWO4

2014 ◽  
Vol 451 ◽  
pp. 80-83 ◽  
Author(s):  
Chang-Chun Ding ◽  
Shao-Yi Wu ◽  
Min-Quan Kuang ◽  
Yong-Kun Cheng ◽  
Li-Juan Zhang
Keyword(s):  
Local Structure ◽  
Theoretical Studies ◽  
Spin Hamiltonian ◽  
Hamiltonian Parameters
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