Three-dimensional Dirac semimetals: Design principles and predictions of new materials

Design principles and predictions of new three-dimensional (3D) Dirac semimetals are presented and placed in the context of currently known materials. Three different design principles are presented (cases I, II, and III), each of which yields predictions for new candidates. For case I, 3D Dirac semimetals based on charge-balanced compounds BaAgBi, SrAgBi, YbAuSb, PtBi₂, and SrSn₂As₂ are identified as candidates. For case II, 3D Dirac semimetals in analogy to graphene, BaGa₂ is identified as a candidate, and BaPt and Li₂Pt are discussed. For case III, 3D Dirac semimetals based on glide planes and screw axes, TlMo₃Te₃ and the AMo₃X₃ family, in general (A=K, Na, In, Tl; X=Se, Te), as well as the Group IVb trihalides such as HfI₃, are identified as candidates. Finally, we discuss conventional intermetallic compounds with Dirac cones and identify Cr₂B as a potentially interesting material.