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Angular variation of electron paramagnetic resonance spectrum: simulation of a polycrystalline EPR spectrum.

J Magn Reson. 1999 Mar;137(1):83-92

Authors: Misra SK

Abstract

A procedure based on homotopy, involving a quick calculation of EPR line positions for various orientations of the external magnetic field by the method of least-squares fitting and Taylor-series expansion, using a known line position at an infinitesimally close orientation of the external magnetic field as the initial value, by using the eigenvectors and eigenvalues of the spin-Hamiltonian matrix in single crystals, has been exploited to simulate a polycrystalline EPR spectrum. This requires rigorous calculations of intensities of resonant lines, along with their positions. Specifically, details are given of the numerical techniques involving time-efficient matrix diagonalization to obtain the eigenvalues and eigenvectors required to calculate positions and intensities of EPR lines by the method of least-squares fitting. Finally, the procedure of how to simulate a polycrystalline EPR spectrum is outlined, the required steps are listed, and illustrative examples are given.

PMID: 10053135 [PubMed - indexed for MEDLINE]