Guillain-Barré syndrome after lightning strike

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• 作者：Panagiotis Theodorou ; Volker Limmroth ; Walter Perbix ; Mark Gerbershagen ; Friedrich Knam ; Gerald Spilker
• 关键词：Spin-Hamiltonian (SH) parameters ; Electron paramagnetic resonance (EPR) ; Crystal- and ligand-field theory ; Charge-transfer mechanism ; Ni²⁺ ; CsMgX₃ (X=Cl ; Br ; I)
• 刊名：Burns
• 出版年：2008
• 出版时间：August 2008
• 年：2008
• 卷：34
• 期：5
• 页码：722-726
• 全文大小：1210 K

文摘

In this paper, the high-order perturbation formulas of spin-Hamiltonian (SH) parameters (g factors g, g and zero-field splitting D), including both the crystal-field (CF) and for the first time charge-transfer (CT) mechanisms, are established for 3d⁸ ions in trigonal octahedral clusters. By using these formulas, the SH parameters of Ni²⁺ ions in CsMgX₃ (X=Cl, Br, I) crystals are calculated. The results are consistent with the experimental values. The calculations suggest that the sign of Q^CT (Q=Δg, Δg or D, where the g-shift Δg_i=g_i−g_e, g_e≈2.0023 is the value of free-electron) due to CT mechanism is the same as that of the corresponding Q^CF due to CF mechanism, and the relative importance of CT mechanism (characterized by Q^CT/Q^CF) increases with the increasing atomic number of ligand X. So, for the 3dⁿ ML_m clusters with ligand having large atomic number, the reasonable theoretical explanations of all SH parameters should take both CF and CT mechanisms into account. The defect structure of (NiX₆)⁴⁻ impurity centers in CsMgX₃:Ni²⁺ crystals is also considered in our model.