Fig. 3: Density functional theory (DFT) calculations of both the charge densities and the electronic band structures at the zigzag (ZZ) edges in monolayer NbSe2.

a–c Atomic configurations of the monolayer NbSe2 ZZ nanoribbons with type-I (ZZ-Se), type-II (ZZ-Nb-Se), and type-III (ZZ-Nb) edges, respectively. The spatially resolved charge densities at Fermi energy (EF) are superposed on the configurations. d–f Electronic band structures for the type-I, II, III edges in monolayer NbSe2. The edge states are highlighted by the colored dots, and the sizes of the dots represent the proportion of the edge Se/Nb orbitals to the energy bands. The Fermi energy EF is marked by the dashed lines.