ELDOR-detected NMR VS symmetry

[Sharon]

Dear someone,

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).

I would be really appreciated if someone can help.

Best,
Sharon

[Stefan Stoll]

The symmetry of the required grid for powder integration depends on the symmetry of the Hamiltonian. You cannot use a grid symmetry higher than the Hamiltonian symmetry - this will give incorrect spectra. The lowest symmetry, Ci, always works.