EasySpin forum

Trying to better understand custom simulation functions, I previously got around to making a custom function that fixes two J's together and keeps the third distinct ( "Tie selected variables to a common value" ), giving an isosceles magnetic model. Now I am trying to fit the chi*T product...

Thanks for the suggestion! What worked is: Ja = -20.6; Jb = -27.1; gxy = 2; gz = 2; Sys1.S=[5/2 5/2 5/2]; Sys1.g=[gxy gz; gxy gz; gxy gz]; Sys1.Ja = -2*cm*Ja; Sys1.Jb = -2*cm*Jb; Vary1.Ja = 10*cm; Vary1.Jb = 10*cm; Vary1.g = [0 0]; Exp.Field = 1000; Exp.Temperature = T; % Fitting arguments FitOpt.Ou...

Thanks, that sounds great!

OK, so I took another look at the examples on the use of esfit with external functions. One thing that I don't understand is how to deal with several Sys structures, like in my case. I have defined SysA which holds the two "dummy" variables and Sys(i) (i = 1,2,....n) which are the actual s...

Thanks for the pointer Joscha, I will look into it!

Hello everyone, I want to generate n spin systems, all of which are variants of a basic system according to a predefined trigonometric function. The fit is carried out on two external parameters that generate the actual parameters of each individual spin system. My code is: cm=100*clight/1e6; % Conv...

Thanks for the update! Things are now working fine. I just have a question (or feature request): for some systems it is numerically more useful to fit the chi*T vs T instead of the chi vs T data (the form of the curve is more revealing of the magnetic behavior and it is easier to obtain a meaningful...

I am trying to fit my EPR data to a model that considers: -Three S=1/2 spins -Three nuclear spins, each coupled to its own atom's electron spin through an axial hyperfine interaction -Three equal isotropic J couplings between the e-spins -Three equal antisymmetric exchange couplings between the e-sp...

I have successfully ran a few fits to my data and have a couple of issues (version 5.0.18). I will post them under this thread, as I think it is more convenient for future reference. 1. Horizontal scaling I had observed some "weird" appearance of my experimental data and I now know why. It...

This is relevant to the more general post "Tie several variables to a common value" , but in this case I would like to fix together only some of the total variables (i.e. considering a not so symmetric system). E.g., following up from the special case of the model described in "Fittin...