One way of addressing the controversy regarding the nature of bonding in PCMs would be to study materials at HP from both real (bond) and reciprocal (band) perspectives , particularly studying simple p-type elements of groups 15 and 16, which show homoatomic/homonuclear linkages, and are much simpler systems than binary and ternary PCMs . In this work, we follow this approach to illustrate the mechanism of MMB formation in materials at HP from the original primary covalent ppσ-bonds and secondary bonds (related to LEPs) present in elemental pnictogens and chalcogens at room pressure (RP). The reason to study p-type group-15 and -16 elements is that they are LEP-based semiconductors at RP and are the simplest known materials featuring primary covalent ppσ-bonds and secondary bonds at RP. In addition, they have been predicted to transform into MMBs at HP as they approach octahedral coordination, such is the case of the HP phase of sc-Sb . The crystalline structures of pnictogens and chalcogens at RP display a small atomic coordination that satisfy the 8-N rule, except Po, and it is known that the octahedral distortion decreases as pressure increases . In addition, the crystalline structures of group 15 (As, Sb, Bi) and group 16 (Se, Te) elements at RP are considered Jones-Peierls distorted structures of the octahedrally-coordinated sc phase, in the same way as the crystalline structures at RP of most IV-VI and V2-VI3 chalcogens (not PCMs) have been considered to be Jones-Peierls distorted structures of the octahedrally-coordinated cubic rock-salt (rs) phase present in many PCMs .