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EPR in
Semiconductors Spin-Hamiltonian parameter database for EPR centers in semiconductors |
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Help top | Policy | How to prepare *.inp file | Command lines | Author's comment lines | S and I | SH parameter matrices | Rotation matrices | Angular parameters | Transition tables | Parameter output(*.out file) | Graph output(*.plt file) | S=1/2 | S=1/2, I=1/2 | S=1 |
1 0 0 0 1 0 0 0 1 -0.5 -0.866025 0 0.866025 -0.5 0 1. 0 1 -0.5 0.866025 0 -0.866025 -0.5 0 0 0 1 -1 0 0 0 -1 0 0 0 1 0.5 0.866025 0 -0.866025 0.5 0 0 0 1 0.5 -0.866025 0 0.866025 0.5 0 0 0 1 For hexagonal crystals (hexagonal SiC, GaN) in the cartesian coordinate, x=[11-20], y=[-1100], z=[0001]. This set is equivalent to that prepared by ROTGRP=C6. NSITE should be 6. What are rotation matrices?With crystals, we frequently observe multiple EPR lines in a spectrum, which correspond to chemically-equivalent EPR centers with different orientations. The number of such equivalent centers is determined by the symmetry of the crystal. We call them “symmetry-related centers or sites”. Among these sites, one site feels magnetic field B, while other site feels different field R·B, where R is called “rotation matrix”. So, to simulate complete angular dependence of EPR spectra, we have to define all possible rotation matrices for the relevant crystal. In principle, there are 11 sets of rotation matrices, which are automatically generated by ROTGRP option in command lines. However, we prefer a manual set (ROTGRP=OFF) rather than the automatic set, because rotation matrices vary with not only the crystal symmetry but also the choice of a coordinate system. Therefore, rotation matrices implicitly determine how we choose the experimental Cartesian coordinate. Here, two standard sets applicable to most of the important semiconductors are given. These experimental coordinates can be well prepared in actual EPR experiments, and therefore these coordinates have become the standards. We kindly recommend you to use these sets, because of such a reason. |
1 0 0 0 1 0 0 0 1 -1 0 0 0 0 -1 0 -1 0 1 0 0 0 -1 0 0 0 -1 -1 0 0 0 0 1 0 1 0 0 -0.707107 0.707107 0.707107 -0.5 -0.5 0.707107 0.5 0.5 0 0.707107 -0.707107 -0.707107 -0.5 -0.5 -0.707107 0.5 0.5 0 -0.707107 0.707107 -0.707107 0.5 0.5 -0.707107 -0.5 -0.5 0 0.707107 -0.707107 0.707107 0.5 0.5 0.707107 -0.5 -0.5 0 0.707107 0.707107 -0.707107 -0.5 0.5 0.707107 -0.5 0.5 0 -0.707107 -0.707107 0.707107 -0.5 0.5 -0.707107 -0.5 0.5 0 -0.707107 -0.707107 -0.707107 0.5 -0.5 0.707107 0.5 -0.5 0 0.707107 0.707107 0.707107 0.5 -0.5 -0.707107 0.5 -0.5 For diamond or zincblend crystals (Si, GaAs, diamond, c-GaN, 3C-SiC) in the cartesian coordinate, x=[100], y=[011], z=[0-11]. This set is calculated by rotating twelve rotation matrices for ROTGRP=T by 45° around the [100] axis. Then, the coordinate axes are changed such as [010] → [011] and [001] → [0-11]. NSITE should be 12. Each matrix should be separated by empty line(s). The number of rotation matrices should equal to NSITE in command lines. |