Methods for automated analysis and simulation of electron paramagnetic resonance spectra

Nonlinear-least-squares analysis of slow motional regime EPR spectra

“…Consistent with the literature, the Newton-based methods, which do well when starting close to the minimum [24], have shown a general high sensitivity towards initial values, which would explain their lower percentage of successful fits. Still, NL2SNO seems less sensitive to starting values than NLSL and NLSL(s), as would be expected, since it starts out with a Gauss-Newton model, which is known to have better initial convergence.…”

Nonlinear-Least-Squares Analysis of Slow-Motion EPR Spectra in One and Two Dimensions Using a Modified Levenberg–Marquardt Algorithm

“…Thus, the appearance of large correlations amongst fitting parameters can be a tionally narrowed spectra have been available for some time (49)(50)(51)(52), such an approach had been prohibitive for slow-useful diagnostic for identifying such cases and determining the intrinsic resolution of the data with respect to the model motion spectra because of the much larger computational burden involved. Critical steps in the extension of such meth-parameters, as we now illustrate.…”

EPR and ENDOR of radicals of chlorin- and bacteriochlorin-quinone model compounds for electron transfer in photosynthesis

“…A possible reason why such hfcs are not observed for Zn-2b −ž is that only in Zn-1b −ž and 3b −ž the quinone is located next to a saturated pyrrole ring and that these small hfcs are due to the protons of the saturated pyrrole ring. Small hfcs are also absent in the directly linked porphyrin quinones, 21 suggesting additionally that the hfcs are larger in the (bacterio)chlorin cases because theˇ-protons of the saturated pyrrole ring are not in the plane of the chlorin -electron system. From general TRIPLE resonance spectroscopy the signs of the small hfcs of …”