摘要
This paper systematically investigates the local distortion and electron paramagnetic resonance （EPR） parameter for CdCl2：V^2＋ and CsMgX3：V^2＋ （X=Cl, Br） systems on the basis of the complete energy matrix, in which not only the contributions due to the spin-orbit coupling of the central ions but also that of the ligands are considered. To describe the difference of overlapping between d-orbits and p orbit, two spin-orbit coupling coefficients are introduced. By simulating the crystal field parameter and EPR parameter, the local distortion parameters are studied and the relationships between the EPR parameter and the spin-orbit coupling coefficients as well as divergent parameter are discussed. These results show that the local structures exhibit compression distortion for CdCl2：V^2＋ and elongation distortions for CsMgX3：V^2＋ （X：Cl, Br）, respectively. It notes that the empirical formula R≈RH T （ri - rh）/2 is not suitable for CdCl2：V^2＋ and CsMgX3：V^2＋ （X=Cl, Br） systems. The contributions of ligand to spin-orbit coupling interaction cannot be neglected for strong covalent systems, especially for V^2＋ doped in CsMgBr3：V^2＋.
This paper systematically investigates the local distortion and electron paramagnetic resonance （EPR） parameter for CdCl2：V^2＋ and CsMgX3：V^2＋ （X=Cl, Br） systems on the basis of the complete energy matrix, in which not only the contributions due to the spin-orbit coupling of the central ions but also that of the ligands are considered. To describe the difference of overlapping between d-orbits and p orbit, two spin-orbit coupling coefficients are introduced. By simulating the crystal field parameter and EPR parameter, the local distortion parameters are studied and the relationships between the EPR parameter and the spin-orbit coupling coefficients as well as divergent parameter are discussed. These results show that the local structures exhibit compression distortion for CdCl2：V^2＋ and elongation distortions for CsMgX3：V^2＋ （X：Cl, Br）, respectively. It notes that the empirical formula R≈RH T （ri - rh）/2 is not suitable for CdCl2：V^2＋ and CsMgX3：V^2＋ （X=Cl, Br） systems. The contributions of ligand to spin-orbit coupling interaction cannot be neglected for strong covalent systems, especially for V^2＋ doped in CsMgBr3：V^2＋.
基金
Project supported by the National Natural Science Foundation of China (Grant Nos. 10774103 and 10974138)
