Electronic structure and static dielectric response of Ba(Mn1/3Nb2/3)O3 from first principles

The electronic structure and dielectric properties of Ba(Mn1/3Nb2/3)O3 have been studied in the framework of the GGA(PBE)+U implementation of density functional theory. We show that Ba(Mn1/3Nb2/3)O3 is a typical Mott–Hubbard insulator which is characterized by the Mn 3d(eg)–Nb 4d(t2g) band gap. Excellent agreement between calculated and measured dielectric constants can be obtained only when taking suitable on-site Coulomb interaction parameters in both Mn 3d and Nd 4d electronic orbitals.