Wave-function-based approach to quasiparticle bands: Insight into the electronic structure of c-ZnS

Article

关键词: CONFIGURATION-INTERACTION CALCULATIONS;    CORRELATED MOLECULAR CALCULATIONS;    PLESSET PERTURBATION-THEORY;    BROKEN ORBITAL-SYMMETRY;    COMPOSITE ENERGY-BANDS;    COUPLED-CLUSTER THEORY;    AB-INITIO CALCULATIONS;    GAUSSIAN-BASIS SETS;    II-VI-COMPOUNDS;    PERIODIC-SYSTEMS;   

DOI  :  10.1103/PhysRevB.83.205119

来源: SCIE

【 摘 要 】

Ab initio wave-function-based methods are employed for the study of quasiparticle energy bands of zinc-blende ZnS, with focus on the Zn 3d semicore states. The relative energies of these states with respect to the top of the S 3p valence bands appear to be poorly described as compared to experimental values not only within the local density approximation (LDA), but also when many-body corrections within the GW approximation are applied to the LDA or LDA+ U mean-field solutions [T. Miyake, P. Zhang, M. L. Cohen, and S. G. Louie, Phys. Rev. B 74, 245213 (2006)]. In the present study, we show that for the accurate description of the Zn 3d states a correlation treatment based on wave-function methods is needed. Our study rests on a local Hamiltonian approach which rigorously describes the short-range polarization and charge redistribution effects around an extra hole or electron placed into the valence respective conduction bands of semiconductors and insulators. The method also facilitates the computation of electron correlation effects beyond relaxation and polarization. The electron correlation treatment is performed on finite clusters cut off the infinite system. The formalism makes use of localized Wannier functions and embedding potentials derived explicitly from prior periodic Hartree-Fock calculations. The on-site and nearest-neighbor charge relaxation lead to corrections of several eV to the Hartree-Fock band energies and gap. Corrections due to long-range polarization are of the order of 1.0 eV. The dispersion of the Hartree-Fock bands is only slightly affected by electron correlations. We find the Zn 3d semicore states to lie similar to 9.0 eV below the top of the S 3p valence bands, in very good agreement with values from valence-band x-ray photoemission.

【 授权许可】

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