Ab initio studies of the structural and electronic properties of solid cubane

In this paper, we report ab initio calculation of the structural and electronic properties of solid cubane $\left({\mathrm{s}-\mathrm{C}}_8{\mathrm{H}}_8\right)$ in the local-density approximation. By using an ab initio constant pressure extended molecular dynamics method with variable cell shape proposed by Wentzcovitch, Martins, and Price, we compute a lattice parameter a and a bond angle $\alpha$ for the rhombohedral Bravais lattice and compare it with experimental x-ray data. We obtain bond lengths for the mononuclear ${\mathrm{C}}_8{\mathrm{H}}_8$ unit of basis atoms, as well as a density of states and heat of formation.