Quantitative test of electronic structures of organic ferromagnet systems from first-principles investigations using muon spin rotation data

The electronic structure of the organic ferromagnet 4-(p- chlorobenzylideneamino)-TEMPO is determined by the first-principles unrestricted Hartree-Fock cluster procedure, with and without muon (μ) and muonium (Mu), and its accuracy is tested by investigating μ and Mu trapping sites and corresponding muon hyperfine interaction tensors. The results provide good agreement with the observed muon spin rotation frequency, site assignment, and also easy-axis direction in agreement with that from dipole-dipole interactions between the calculated distributed magnetizations in the molecules.