Irr sph ten.m
Returns a cell array of single-spin irreducible spherical tensor operators T(k,m). A two-argument call
where 'mult' is the multiplicity of the spin in question and 'k' is the irreducible spherical tensor rank required, returns a cell array of tensors of that rank in the order of decreasing projection. A single argument call
produces tensors of all ranks and concatenates them into a cell array in the order of ascending rank.
The resulting spherical tensors are normalized in such a way as to obey the following commutation relation:
Note: operator normalization in spin dynamics is an old and thorny question. Many different conventions exist, but the only way to make the resulting formalism independent of the total spin quantum number is to impose identical commutation relations rather than equal matrix norms.