Answers are grounded in this paper and cite their sources.
Simple symmetry properties of the spin operators are used to establish the connection between the electron spin-spin coupling operator, the spin Hamiltonian for the zero-field splitting of a triplet or higher spin state, and the spin coupling function derived by McWeeny from the two-particle density matrix.
No takes yet. Share an insight, caveat, or question.
A. McLachlan (1963) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: