As a summary of this section, we conclude that: i) Polonium is the only chalcogenide that shows fully symmetric MMBs at RP in either of the two known octahedrally-coordinated polymorphs and ii) group-15 (group-16) elements undergo a pressure-induced PT from the A7 (A8) phases, featuring a mixture of primary covalent ppσ-bonds and secondary bonds with LEPs at RP, to HP phases that show MMBs as the octahedral coordination is approached. Whereas the Ah phase is preferred for group-15 elements at HP, the Ai phase is preferred for group-16 elements at HP. In addition, we have shown that the change from the pre-MMB scenario to the MMB scenario is anticipated, for instance, by two measurable magnitudes: i) the change (from negative to positive pressure coefficient) in the optical phonon frequencies, i.e. sign change in Grüneisen parameters and ii) the increase of the average Born effective charge. The MMB scenario occurs at a smaller pressure along the series As-Sb-Bi and Se-Te-Po; a result consistent with the smaller structural distortion of Bi-I (Te-I) than Sb-I and As-I (Se-I) with respect to the Ah (Ai) phase. This result agrees with previous studies that relate the stronger structural distortion in different materials with larger s-p mixing and consequently with stronger LEP stereoactivity . Consequently, our results are consistent with the equivalence of the effect of pressure and change of composition when going down the group to heavier elements in the periodic table , since pressure reduces the LEP stereoactivity in the same way as composition. Finally, we have concluded that the ES and ET values provided by the QTAIM theory not only confirm that bonds in the octahedrally-coordinated phases of pnictogens and chalcogens are MMBs but also can be used to trace in the 2D map the primary covalent bonds and the MMBs in the different crystalline phases of these elemental families and their changes with pressure and composition.