ELDOR-detected NMR VS symmetry!!

[NOAhgomes]

Recently I have been working on the simulation of EDNMR for an spin half and half powder system using the code provided by Anton.Savitsky. It turns out if I specified different symmetry in the simulation, the NMR intensity will be different. I checked the code, which use sphgrid function to generates triangular grids of orientations over parts of the unit sphere and symmetry specifies the symmetry for which the grid is to be generated,different symmetry will have different unique surface, which means in the simulation, they use different part of the unit sphere. But I am confused how the NMR intensity can be influenced by the choices of the symmetry (some symmetries will give the same intensity, but some will not).

[nwili]

I think I encountered the same problem. The problem comes from the symmetry treatment. If you use another symmetry than Ci, you also have to align your system along the symmetry axis, this is not necessarily the case!

[nwili]

I might have overthought your question. If you you do not use the symmetry of your spin system, you do not sample the orientational grid correctly.

[Stefan Stoll]

C1 or Ci symmetry should work always, also for low-symmetry spin Hamiltonians.