Figure 2. Schematic description of the vacancy and the foreign atom doped M-BP.

. Here, violent balls represent the P atoms of M-BP. The configuration of single vacancy M-BP can be obtained by removing P₁ atom. The various configurations of the divacancy can be obtained by removing P₁-P₂, P₁-P₃, P₁-P₄, P₁-P₅, P₁-P₆, P₁-P₇, and P₁-P₈ atoms, respectively. The corresponding doped configurations are obtained by replacing the P atoms by the doping atoms.