Karin Fink: Quantum Chemistry for Single Molecule Magnets

Single molecule magnets (SMMs) are compounds with a non-vanishing total spin S which show slow relaxation of the magnetization often caused by magnetic anisotropy. Typical SMMs are mononuclear and exchange coupled transition metal compounds with first order spin orbit effects. In electronic structure calculations, the multi reference character of the wave functions as well as spin orbit coupling has to be taken into account, e.g. by spin orbit configuration interaction (SOCI). Dynamic correlation effects are considered by shifting the diagonal terms of the SOCI matrix. Zero-field splittings and g-tensors are extracted by means of effective Hamiltonian theory. Using these methods, approximate spin-reversal barriers and magnetic axes were calculated for complexes containing Co2+ and Ni2+ ions.