Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 63: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles IV (jointly with TT)

O 63.6: Vortrag

Donnerstag, 29. März 2012, 12:00–12:15, HE 101

DFT and beyond-DFT derived tight-binding parameters for RMnO₃ using the VASP2WANNIER90 interface — •Sowmya Sathyanarayana Murthy¹, Roman Kovacik², Martijn Marsman¹, Cesare Ederer², Georg Kresse¹, and Cesare Franchini¹ — ¹Faculty of Physics, University of Vienna and Center for Computational Materials Science, A-1090 Wien, Austria — ²School of Physics, Trinity College Dublin, Dublin 2, Ireland

By combining the Vienna ab initio simulation package with the wannier90 code we have constructed maximally localized Wannier functions (MLWFs) for the Jahn-Teller/GdFeO₃ distorted insulating perovskites RMnO₃ (R=La, Pr, Nd, Sm and Eu) at different levels of approximation for the exchange-correlation kernel (PBE, HSE and GW)[1]. By suitably mapping the MLWFs onto an effective e_g tight-binding (TB) Hamiltonian[1,2] we have computed a complete set of TB parameters using two alternative model parameterizations, with and without an explicit treatment of the electron-electron interaction. The so obtained set of tabulated TB parameters provide band dispersion in excellent agreement with the underlying ab initio and MLWF bands. The evolution of the structural and electronic properties of RMnO₃ as a function of the atomic radius of R[3] is discussed in terms of the corresponding changes in the TB parameters and MLWFs properties.

References:

[1] C. Franchini at. al arXiv:1111.1528 (2011).

[2] R. Kovacik & C. Ederer Phys. Rev. B 81 245108 (2010).

[3] T.Kimura et al. Phys. Rev. B 68 060403(R) (2003).