EasySpin forum

Hello
I have a question regarding simulation of Cu EPR spectra in frozen solution. Often the linewidth of the four lines of the g// region are different and the peaks are getting broader as the field increases (this is particularly clear in the case of CuSO4 frozen solution spectrum), sometimes the order is reversed (lines getting narrower, but this is more rare in my experience).
I haven't found the way yet to reproduce that with EasySpin. I have used g- or better H-strain but it doesn’t work or the broadening is not in the correct order.
Do you know what I should be using to reproduce this ? Is using slow-motion spectra the way to go around it ? I haven't looked into that yet.
Thanks

Pierre, you should use Sys.gStrain and Sys.AStrain together. In Cu systems, the g and the A values are typically correlated, so you need also to specify this correlation. This can be done in Sys.gAStrainCorr. This field can have two values:
I just noticed that this is missing in the documentation. Will be fixed in the next release.

Hi Stefan, thank you very much for the quick reply.
Pierre