Determination of the g-, hyperfine coupling- and zero-field splitting tensors in EPR and ENDOR using extended Matlab codes

Autor: Anders Lund, Freddy Callens, Einar Sagstuen
Rok vydání: 2020
Předmět:
Zdroj: Journal of magnetic resonance (San Diego, Calif. : 1997). 325
ISSN: 1096-0856
1090-7807
Popis: The analysis of single crystal electron magnetic resonance (EMR) data has traditionally been performed using software in programming languages that are difficult to update, are not easily available, or are obsolete. By using a modern script-language with tools for the analysis and graphical display of the data, three MatLab (R) codes were prepared to compute the g, zero-field splitting (zfs) and hyperfine coupling (hfc) tensors from roadmaps obtained by EPR or ENDOR measurements in three crystal planes. Schonlands original method was used to compute the g- and hfc-tensors by a least-squares fit to the experimental data in each plane. The modifications required for the analysis of the zfs of radical pairs with S = 1 were accounted for. A non-linear fit was employed in a second code to obtain the hfc-tensor from EPR measurements, taking the nuclear Zeeman interaction of an I = 1/2 nucleus into account. A previously developed method to calculate the g- and hfc -tensors by a simultaneous linear fit to all data was used in the third code. The validity of the methods was examined by comparison with results obtained experimentally, and by roadmaps computed by exact diagonalization. The probable errors were estimated using functions for regression analysis available in MatLab. The software will be published at https://doi.org/10.17632/ps24sw95gz.1, Input and output examples presented in this work can also be downloaded from https://old.liu.se/simarc/downloads?l=en. (C) 2021 The Author(s). Published by Elsevier Inc. Funding Agencies|Linkoping University; Ghent UniversityGhent University; University of Oslo
Databáze: OpenAIRE