Energy bands and Fermi surface of Sr2RuO4

A method combining the extended Huckel theory and the tight-binding approxi mation is proposed to study the electronic properties of the layered noncup rate superconductor Sr2RuO4 The band structure close to the Fermi level is obtained by integrating out all low-lying oxygen degrees of freedom allowin g the determination of the energy spectra, the Fermi surface, and the total density of states. The results reproduces the main features of local-densi ty approximation calculations near the Fermi energy. As an application of t he approach here proposed, we have calculated the temperature dependence of the in-plane Hall coefficient considering the effect of the curvature of t he Fermi surface. [S0163-1829(99)11903-9].