Electronic structure of two-dimensional crystals from ab initio theory

摘要: We report on ab initio calculations of the two-dimensional systems ${\text{MoS}}_{2}$ and ${\text{NbSe}}_{2}$, which recently were synthesized. find that is a semiconductor with gap rather close to three-dimensional analog, ${\text{NbSe}}_{2}$ metal, similar analog this compound. further computed electronic structure hexagonal (graphene-like) lattices Si Ge compared them graphene. It found properties related Dirac cone do not appear in case germanium, metallic, contrary silicon, also known as silicene, has an very one graphene, making possibly equivalent.