question to lwpp for spin S = 3/2

[matthias]

Hello,

in the documentation for lwpp it is noted, that for spin S > 1/2 this value leads to incorrect results. I want to simulate a quite simple system with pepper: S = 3/2, isotropic g-value g = 0.777, isotropic hyperfine coupling to 14N A(14N) = 31 MHz, axial zero field splitting parameter D = 57 MHz, single crystal (one orientation in z-direction). So in this direction mS is still a good quantum number. The only line width parameter I introduce is lwpp. My question is, if for this simple system lwpp still gives the correct peak-to-peak line width of a homogeneous Lorentzian line broadening (due to a simple exponential life time process).

Regards,

Matthias

[Stefan Stoll]

lwpp is a purely convolutional broadening. This means that ES first simulates a broadening-free stick spectrum and convolves it with a line shape (Gaussian/Lorentzian). As a result, all lines in a field-sweep spectrum will be broadened equally. If that's what you are seeing in your spectrum, then you can use it safely.

As long as all the anisotropies are small (as in your case), then lwpp is reasonable. However, be mindful that sometimes lifetimes can be anisotropic.