Unconventional magnetism as a consequence of the charge disproportionation and the molecular orbital formation in Ba4Ru3O10

The magnetic and electronic properties of Ba${}_4$Ru${}_3$O${}_{10}$ were investigated by the ab-initio and model calculations. It is shown that nonmagnetic ground state of the one-third Ru${}^{4+}$ ions is not due to the correlation effects. It is rather caused by the charge disproportionation between crystallographically different Ru and the molecular orbital formation in the Ru’s trimer.