Rapid analysis of the anisotropic EPR spectra of polycrystalline and amorphous systems formed by species with orthorhombic symmetry of the g value

A new method has been proposed for determining the magnetic resonance parameters (g-values, line widths) from the EPR spectra of vitrified solutions and powders of species with orthorhombic symmetry of the g value and spin S = 1/2. The method has an accuracy comparable with that of computer modeling of the spectra, and at the same time is extremely simple, since it does not require complex mathematical calculations. The approach is based on the expansion of the integral expression describing the vitreous EPR spectrum into a rapidly converging series from which analytical expressions are obtained. Comparison of the approximate spectra with spectra modeled using a computer showed good agreement. The analytical expressions have been used to obtain a number of simple rules (not requiring a computer) for obtaining magnetic resonance parameters from the spectra with a good accuracy