(color online) Crystal structures of α-MoB₂ and MoS₂. Large white spheres represent Mo atoms, small blue spheres are B atoms. (a) α-MoB₂ (P6/mmm) structure with AH stacking sequence. (b) Crystal structure of MoS₂. (c) Three-dimensional metallic Mo–Mo framework in α-MoB₂. (d) Two-dimensional graphene-like borophene units in α-MoB₂.