Abstract
Band structure of the ferrimagnetic Fe3O4 was calculated in the high temperature cubic phase by means of the full-potential linearized augmented-plane-wave method with the local spin density approximation. In the majority spin bands, the Fermi level stays in the band gap and 3d states of A site Fe are unoccupied while 3d states of B site Fe are completely occupied. In the minority spin bands, 3d states of A site are occupied and the Fermi level stays in dε bands of B site Fe. The obtained Fermi surfaces well explain the mechanism of the structural phase transition in Fe3O4. The calculated charge density has good correspondence to the recent experimental results.