Hi everyone. I am trying to simulate a pulsed ENDOR spectrum registered with Davies sequence. I noticed that saffron does not support the Davies ENDOR sequence, while if I try with salt it doesn't really reproduce the very intense central part of the spectrum (I tried adding a gaussian or a lornezian centered at Larmor frequency but the effect is not that good). I also tried to define the pulse sequence with Exp.Sequence in saffron but I don't really know how to define the rf pi pulse and it also gives me an error saying "reference to non-existent field 'Dim1'".
Any suggestion on what I can do?
Dear Angelo,
Salt is the most suitable approach here usually. How far exactly did you get with that?
The very intense central peak is usually a so-called matrix peak that arises from many many very small hyperfine couplings (such as matrix protons, hence the name). Could that also be the case here?
This is often not accounted for in the simulations.
Otherwise, what's your system? With knowing more it would be easier to help.
The problem is that I have a very broad matrix peak with other hyperfine couplings that can be seen on top of that (it kinda looks like a christmas tree, I know it's not the best way to depict it but I have no other idea).
So the main problem is reproducing this very broad feature and then adding the peaks due to the hfcs that I can actually measure
So since you know that this is a matrix peak, you can approximate this by a Gaussian centered at the Zeeman frequency of the respective nucleus. This Gaussian you can either subtract or, perhaps more elegant, include in a User-defined simulation function in addition to the ENDOR simulation to model the peaks you have due to resolved hyperfine couplings (see ES documentation, Least-squares fitting -> User-defined simulation function).