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 AMo(3)X(3) 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.