Electronic and geometrical structure and magnetic ordering in passivated Mn12O12-acetate nanomagnets

We performed electronic structure calculations on several Mn12O12 and Mn12O12(COOH)16(H2O)4 clusters to investigate the magnetic ordering and the role of the ligands in stabilizing the D2 structure of the MnO core. Without passivation, an antiferromagnetic tower is more stable than the free D2 Mn12O12 core, but the ligands stabilize the D2 symmetry which leads to ferrimagnetic ordering and a net moment of 20 μB. Local Mn moments are presented and the electronic states most responsible for formation of the spin tunneling barrier are identified.