As in previous works , our investigations are based on calculations of energies, structures, and derived properties within the density functional theory (DFT) quantum mechanics framework . Specifically, superdense qtz BP and AlP were found to be cohesive, albeit with smaller magnitudes than known for zinc-blende BP and AlP with dia topology (vide infra, section 3.1), and were identified as stable both mechanically (elastic constants) and dynamically (phonon band structures). From the establishment of the respective equations of states (EOS), the trends of zb-BP and zb-AlP transformations to qtz high-pressure forms maintaining a tetrahedral coordination have been identified. The electronic band structures of the new qtz phases show reduced band gaps compared to zinc-blende polymorphs.