Azarkh Mykhailo, Groenen Edgar J J
Huygens-Kamerlingh Onnes Laboratory, Department of Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
Huygens-Kamerlingh Onnes Laboratory, Department of Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
J Magn Reson. 2015 Jun;255:106-13. doi: 10.1016/j.jmr.2015.04.006. Epub 2015 Apr 24.
We present a numerical procedure called 'grid-of-errors' to extract the distribution of magnetic interactions from continuous-wave electron-paramagnetic-resonance (EPR) spectra at multiple microwave frequencies. The approach is based on the analysis of the lineshape of the spectra and explicitly worked out for high-spin systems for which the lineshape is determined by a distribution of the zero-field splitting. Initial principal values of the zero-field splitting tensor are obtained from the EPR spectrum at a microwave frequency in the high-field limit, and the initial distribution is taken Gaussian. Subsequently, the grid-of-errors procedure optimizes this distribution, without any restriction to its shape, taking into account spectra at various microwave frequencies. The numerical procedure is illustrated for the Fe(III)-EDTA complex. An optimized distribution of the zero-field splitting is obtained, which provides a proper description of the EPR spectra at 9.5, 34, 94, and 275 GHz. The proposed approach can be used as well for distributions of magnetic interactions other than the zero-field splitting.
我们提出了一种名为“误差网格”的数值方法，用于从多个微波频率下的连续波电子顺磁共振（EPR）光谱中提取磁相互作用的分布。该方法基于对光谱线形的分析，并针对高自旋系统进行了明确推导，对于这类系统，线形由零场分裂的分布决定。零场分裂张量的初始主值是从高场极限下微波频率的EPR光谱中获得的，初始分布采用高斯分布。随后，误差网格程序对该分布进行优化，不受其形状的任何限制，同时考虑了不同微波频率下的光谱。通过Fe(III)-EDTA配合物对该数值方法进行了说明。得到了零场分裂的优化分布，该分布能恰当地描述9.5、34、94和275 GHz下的EPR光谱。所提出的方法也可用于除零场分裂之外的磁相互作用分布。
