First-principles investigation ofReO3sand related oxides

Abstract

Electronic-structure calculations are performed, within the local-density approximation to the density-functional theory, using the full-potential linear muffin-tin orbital method to understand the relation between structural and electronic properties of ${\mathrm{ReO}}_{3}$ , ${\mathrm{WO}}_{3}$ , and the stoichiometric tungsten bronze ${\mathrm{NaWO}}_{3}$ . Energy changes associated with small deformations from the cubic phase indicate that ${\mathrm{ReO}}_{3}$ and the tungsten bronze are stable when cubic while the W ion in ${\mathrm{WO}}_{3}$ shows a tendency to off-center displacements. The different behavior is explained by examining the band structure of the compounds. Calculated frequencies and eigenvectors of \ensuremath{\Gamma} phonons in ${\mathrm{ReO}}_{3}$ corroborate the existence of high-frequency modes in this crystal which supports a recent theoretical proposal for the interpretation of its electrical resistivity.