HYSCORE powder spectrum outline.
nucfrq2d(Sys,B0) nucfrq2d(Sys,B0,tauvec)
nucfrq2d
computes and plots the outline of a HYSCORE powder spectrum.
Peaks positions are accurate, but all peak intensities are set to 1.
The plot thus only shows correlation patterns.
Sys
is the spin system structure defining the spin Hamiltonian.
In Sys
, the electron spin must be 1/2.
B0
gives the magnitude of the external magnetic field, in mT.
tauvec
is a vector of tau values, in microseconds.
It is used to plot blind spot regions, where the ESEEM signal is suppressed.
The plot shows two octants as is standard for HYSCORE spectra and displays all nuclear frequency correlations in color. Peaks that correlate frequencies from the α electron manifold on the horizontal axis with β frequencies on the vertical axis are in green, the β-α correlations are in red.
If tauvec
is given, a gray-shaded background indicating peak suppression regions (blind spots) is shown.
White indicates no suppression, the darker the gray the stronger the suppression.
Correlation plots can be quite aesthetic. For a fantasy system containing one electron and one 14N nucleus
Sys.g = 2; Sys.Nucs = '14N'; Sys.A = 2 + [-1 -1 2]*2; % MHz Sys.Q = [-1.2 -0.8 2]*1.2; % MHz nucfrq2d(Sys,350);
To observe the peaks due to weakly coupled hydrogens, one best uses several tau values related to the Larmor frequency of hydrogen
Sys.g = 2; Sys.Nucs = '1H'; Sys.A = [-1 -1 2]*4 + 2; % MHz B0 = 350; % mT nuL = larmorfrq(Sys.Nucs,B0); % MHz tauvec = [1.5 2.1]./nuL; % µs nucfrq2d(Sys,B0,tauvec)