scholarly journals Spin-orbit coupling and zero-field splitting of the high-spin ferric enzyme-substrate complex: Protocatechuate 3,4-dioxygenase complexed with 3,4-dihydroxyphenylacetate

2012 ◽  
Vol 58 (6) ◽  
pp. 627-633 ◽  
Author(s):  
LingLing Lü ◽  
YuanCheng Zhu ◽  
XiaoFang Wang ◽  
GuoFang Zuo ◽  
Feng Guo ◽  
...  
Keyword(s):  
High Spin ◽  
Orbit Coupling ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Substrate Complex ◽  
Enzyme Substrate

Studies of EPR Parameters and Local Structure for Cr3+ in NaInS2 Crystal

2005 ◽  
Vol 60 (1-2) ◽  
pp. 91-94
Author(s):  
Yang Mei ◽  
Wen-Chen Zheng ◽  
Xiao-Xuan Wu ◽  
Qing Zhoua
Keyword(s):  
Local Structure ◽  
Coupling Parameter ◽  
Orbit Coupling ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Epr Parameters ◽  
Local Angle

The EPR parameters (zero-field splitting D and g factors g‖, g⊥) of Cr3+ in a NaInS2 crystal are calculated from high-order perturbation formulas based on the two spin-orbit coupling parameter model for the EPR parameters of 3d3 ions in trigonal octahedral sites. In the calculations, both the contribution to EPR parameters from the spin-orbit coupling parameter of the central 3d3 ion and that of ligands are considered. From the calculations it is found that, to explain reasonably the EPR parameters, the local structure (in particular the local trigonal distortion angle θ ) in the vicinity of the Cr3+ impurity is different from the corresponding structure in the host crystal. The change of the local angle θ with temperature is also obtained from the temperature dependence of zero-field splitting. The results are discussed.

Studies of the Zero-Field Splitting for Mn2+ In 6H-RbMgF3 Crystal

2004 ◽  
Vol 59 (12) ◽  
pp. 961-963 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Yang Mei ◽  
Xiao-Xuan Wu ◽  
Qing Zhou
Keyword(s):  
Structural Data ◽  
Orbit Coupling ◽  
Site Symmetry ◽  
Coupling Mechanism ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Superposition Model ◽  
Zero Field Splitting ◽  
Field Splitting

By using the spin-orbit coupling mechanism and the empirical superposition model, the zero-field splittings D of Mn2+ ions on both Mg2+ sites in hexagonal 6H-RbMgF3 crystal are calculated from the structural data of both Mg2+ sites. The calculated results of both methods confirm the suggestion that Mn2+ in 6H-RbMgF3 occupies the Mg2+ (I) site (which has D3d site symmetry) and the zero-field splitting D of 6H-RbMgF3: Mn2+ is explained reasonably.

Spin-Orbit Coupling in Biradicals. 4. Zero-Field Splitting in Triplet Nitrenes, Phosphinidenes, and Arsinidenes

2003 ◽  
Vol 68 (12) ◽  
pp. 2335-2343 ◽  
Author(s):  
Zdeněk Havlas ◽  
Mojmír Kývala ◽  
Josef Michl
Keyword(s):  
Orbit Coupling ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Zero Field Splitting Parameter ◽  
Order Of Magnitude ◽  
Splitting Parameter ◽  
A Minor

The spin dipole-spin dipole and spin-orbit coupling contributions to the zero-field splitting parameter D of CH3-N, CH3-P, CH3-As, SiH3-N, SiH3-P, and SiH3-As have been calculated from CAS(12,11)/cc-pVTZ wave functions and the Breit-Pauli Hamiltonian at T1 B3LYP/cc-pVTZ optimized geometries. The spin-orbit coupling contributions represent a minor correction for the nitrenes, and bring the value computed for methylnitrene from 1.66 to 1.84 cm-1, in good agreement with experiment (1.72 cm-1). They dominate the spin-spin terms by an order of magnitude in phosphinidenes and by more than two orders of magnitude for arsinidenes. The properties of all these perfect axial biradicals follow expectations based on the simple algebraic 2-in-2 model of biradical structure.

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