Plutonium hexaboride is a correlated topological insulator.

We predict that plutonium hexaboride (PuB(6)) is a strongly correlated topological insulator, with Pu in an intermediate valence state of Pu(2.7+). Within the combination of dynamical mean field theory and density functional theory, we show that PuB(6) is an insulator in the bulk, with nontrivial Z(2) topological invariants. Its metallic surface states have a large Fermi pocket at the X[over ¯] point and the Dirac cones inside the bulk derived electronic states, causing a large surface thermal conductivity. PuB(6) has also a very high melting temperature; therefore, it has ideal solid state properties for a nuclear fuel material.