The 2H phase of MoS 2 (Pearson symbol hP6; Strukturbericht designation C7) has space group P6 3 /mmc. Each layer contains Mo surrounded by S in trigonal prismatic coordination. Conversely, the 1T phase (Pearson symbol hP3) has space group P-3m1, and octahedrally-coordinated Mo; with the 1T unit cell containing only one layer, the unit cell has a c parameter slightly less than half the length of that of the 2H unit cell (5.95 Å and 12.30 Å, respectively). The different crystal structures of the two phases result in differences in their electronic band structure as well. The d-orbitals of 2H-MoS 2 are split into three bands: d z, d x -y,xy, and d xz,yz. Of these, only the d z is filled; this combined with the splitting results in a semiconducting material with a bandgap of 1.9eV. 1T-MoS 2, on the other hand, has partially filled d-orbitals which give it a metallic character.