Density functional calculation of equilibrium geometry and electronic structure of pyrite

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ÂÛÎÄ×÷ÕߣºÇñ¹ÚÖÜ Ð¤Ææ ºúÔÀ»ª Ð쾺

ÎÄÕÂÒ³Â룺583 - 586

Key words£ºdensity functional calculation; electronic structure; equilibrium geometry; pyrite

Abstract: The equilibrium geometry and electronic structure of pyrite has been studied using self-consistent density-functional theory within the local density approximation (LDA). The optimum bulk geometry is in good agreement with crystallographic data. The calculated band structure and density of states in the region around the Fermi energy show that valence-band maximum (VBM) is at X (100),ªªand the conduction-band minimum (CBM) is at G (000). The indirect and direct band gaps are 0.6eVªªand 0.74eV,ªªrespectively. The calculated contour map of difference of charge density shows excess charge in nonbonding d electron states on the Fe sites. The density increases between sulfur nuclei and between iron and sulfur nuclei qualitatively reveal that S£­S bond and Fe£­S bond are covalent binding.