The crystal data provided in Table present the converged calculated new atomic positions after full unconstrained geometry optimization with successive calculations at increasing precision of k-mesh in the three respective Brillouin zones. A unique interatomic B-P distance of 1.97 Å is identified for all three polymorphs. The calculated lattice parameter of c-BP (a = 4.541 Å) is in good agreement with the experimental value 4.543 Å . As for the calculated lattice parameters of w-BP (a = 3.195 Å, c = 5.297 Å), they are in good agreement with a = 3.20 Å and c = 5.31 Å values reported in .