Convergence of quasiparticle self-consistent GW calculations of transition-metal monoxides

Article

关键词: ELECTRONIC-STRUCTURE;    MAGNETIC-STRUCTURES;    OPTICAL-PROPERTIES;    NICKEL-OXIDE;    BAND THEORY;    DOPED COO;    MNO;    NIO;    INSULATORS;    SPECTRA;   

DOI  :  10.1103/PhysRevB.91.115105

来源: SCIE

【 摘 要 】

Finding an accurate ab initio approach for calculating the electronic properties of transition-metal oxides has been a problem for several decades. In this paper, we investigate the electronic structure of the transition-metal monoxides MnO, CoO, and NiO in their undistorted rocksalt structure within a fully iterated quasiparticle self-consistent GW (QP(sc)GW) scheme. We study the convergence of the QP(sc)GW method, i.e., how the quasiparticle energy eigenvalues and wave functions converge as a function of the QPscGW iterations, and we compare the converged outputs obtained from different starting wave functions. We find that the convergence is slow and that a one-shot G(0)W(0) calculation does not significantly improve the initial eigenvalues and states. It is important to notice that in some cases the path to convergence may go through energy band reordering which cannot be captured by the simple initial unperturbed Hamiltonian. When we reach a fully iterated solution, the converged density of states, band gaps, and magnetic moments of these oxides are found to be only weakly dependent on the choice of the starting wave functions and in reasonably good agreement with the experiment. Finally, this approach provides a clear picture of the interplay between the various orbitals near the Fermi level of these simple transition-metal monoxides. The results of these accurate ab initio calculations can provide input for models aiming at describing the low-energy physics in these materials.

【 授权许可】

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