Heisenberg Exchange in the case of rigid limit and chaotic orientation of neighboring radicals
EasySpin makes it possible to simulate spectra in the case of Heisenberg Exchange and low radical mobility with chili() if you set the Sys.tcorr large enough. However, as the calculation shows, it is assumed that neighboring radicals in polycrystallites are ordered along the same direction. This can be seen from the fact that at large values of Sys.Exchange, the anisotropy of the g-factor is not averaged.
Is there any possibility of making a calculation on the assumption of a chaotic orientation of neighboring radicals? How difficult is this task in general? Is there anyone in the EPR community who could take it on?
% Effect of Heisenberg exchange in a nitroxide sample
clear, clf, clc
% Nitroxide and experimental parameters
Sys.g = [2.0088, 2.0061, 2.0027];
Sys.Nucs = '14N';
Sys.A = [16 16 86];
Sys.tcorr = 100e-9;
Sys.lw = 0.1;
Opt.LLMK = [16 5 6 16];
Exp.mwFreq = 9.5;
Exp.CenterSweep = [339, 10];
% Loop over range of exchange frequencies, simulation
ExchangeFreq = 10.^linspace(0.1,4,9); % in MHz
for k = 1:numel(ExchangeFreq)
Sys.Exchange = ExchangeFreq(k);
[B,spc(k,:)] = chili(Sys,Exp,Opt);
legendCell{k} = ['ExchangeFreq = ',num2str(ExchangeFreq(k)),' MHz'];
end
stackplot(B,spc);
legend(legendCell);