Electronic structure of A V 3 Sb 5 kagome metals

The kagome metals $A$V${}_{3}$Sb${}_{5}$ ($A$=K, Rb, Cs) exhibit many intriguing correlated and topological electronic states. Understanding their multiorbital electronic band structure remains a challenge. The authors point out here the unusual and puzzling properties of the density functional theory electronic structure, including the double pure-sublattice-type van Hove singularities, their orbital content, and the geometric shape of the Fermi surface. A generalized multiorbital Slater-Koster approach is developed, which successfully solves these fundamental puzzles and produces a faithful multiorbital tight-binding model description of the electronic structure for kagome metals.