Figure 1: Crystal structure and Brillouin zone of 3D Pentagon Carbon.

(a) Structure of 3D Pentagon Carbon, where the purple lines depict the conventional unit cell, and the red and blue Carbon atoms form mutually orthogonal armchair chains which are linked by the green atoms. This structure can also be viewed as composed of orthogonal pentagonal rings sharing the vertex green atoms, as shown in b. (c) Primitive cell of 3D Pentagon Carbon. The red and blue atoms are marked as C1 sites and the green atoms are marked as C2 sites, indicating their different orbital hybridization character. The lattice parameters of the primitive cell are a=b=c=7.15 Å, α=β=149.86°, γ=43.11°. (d) Top view (from z-axis) of the structure, showing that the red and blue armchair chains are mutually orthogonal. (e) Brillouin zone of the primitive cell along with the high-symmetry points marked.