title: Maximally localized Wannier functions in LaMnO3 within PBE + U, hybrid functionals and partially self-consistent GW: an efficient route to construct ab initio tight-binding parameters for eg perovskites.
abstract: Using the newly developed VASP2WANNIER90 interface we have constructed maximally localized Wannier functions (MLWFs) for the e(g) states of the prototypical Jahn-Teller magnetic perovskite LaMnO(3) at different levels of approximation for the exchange-correlation kernel. These include conventional density functional theory (DFT) with and without the additional on-site Hubbard U term, hybrid DFT and partially self-consistent GW. By suitably mapping the MLWFs onto an effective e(g) tight-binding (TB) Hamiltonian we have computed a complete set of TB parameters which should serve as guidance for more elaborate treatments of correlation effects in effective Hamiltonian-based approaches. The method-dependent changes of the calculated TB parameters and their interplay with the electron-electron (el-el) interaction term are discussed and interpreted. We discuss two alternative model parameterizations: one in which the effects of the el-el interaction are implicitly incorporated in the otherwise 'noninteracting' TB parameters and a second where we include an explicit mean-field el-el interaction term in the TB Hamiltonian. Both models yield a set of tabulated TB parameters which provide the band dispersion in excellent agreement with the underlying ab initio and MLWF bands.
authors.affiliation: Faculty of Physics, University of Vienna and Center for Computational Materials Science, Wien, Austria. cesare.franchini@univie.ac.at
authors.forename: C
authors.initials: C
authors.lastname: Franchini
authors.forename: R
authors.initials: R
authors.lastname: Kováčik
authors.forename: M
authors.initials: M
authors.lastname: Marsman
authors.forename: S Sathyanarayana
authors.initials: SS
authors.lastname: Murthy
authors.forename: J
authors.initials: J
authors.lastname: He
authors.forename: C
authors.initials: C
authors.lastname: Ederer
authors.forename: G
authors.initials: G
authors.lastname: Kresse