Importance of Coulomb correlation and spin-orbit coupling in a 5d pyrochlore: Pr<SUB>2</SUB>Ir<SUB>2</SUB>O<SUB>7</SUB>

Employing state-of-the-art ab initio electronic band-structure calculations, we investigate the electronic structure of an interesting pyrochlore, Pr2Ir2O7 exhibiting varied electronic and magnetic properties. The calculated results indicate that the derivation of the bulk properties requires consideration of spin-orbit coupling and finite on-site Coulomb interaction strength despite the fact that Ir 5d electronic states are expected to be highly extended. Ir 5d moment is found to be finite and couples ferromagnetically with the Pr 4f moments. The magnetic moment and the density of states at the Fermi level depend on the direction of magnetization considered in the calculations suggesting the highly anisotropic magnetic and electronic-transport behavior for this compound consistent with the experimental observations