Remarkably, Hoffmann and coworkers came up with the idea that MMBs in materials, such as sc-Sb, had their origin in secondary bonds or backbonds , i.e. bonds present in rhombohedral Sb at room pressure (RP) and, in general, in materials showing covalent ppσbonds in which the participation of LEPs is important. We consider that to understand the MMB nature in sc-Sb and in PCMs it is essential to realize that the above consideration suggests that there is a mechanism for the MMB formation in sc-Sb. This mechanism involves the transformation of the original primary covalent bonds and secondary bonds into new MMBs. Moreover, Hoffmann and coworkers suggested that secondary bonds, also known as donoracceptor bonds, charge-transfer bonds , or -hole bonds , are similar if not equal to ERMBs/MMBs . Nowadays, several types of secondary bonds, such as hydrogen, triel, tetrel, pnictogen, chalcogen, and halogen bonds, are considered just different types of -hole bonds in line with Hoffmann's view . Secondary bonds are, in fact, one of the workhorses in supramolecular chemistry , and molecular materials such as polyiodides, which according to Hoffmann have a similar bonding as PCMs, are of renewed interest due to their outstanding properties . In this context, it has been reported that it is very difficult to distinguish between the scenario with primary and secondary bonds involving LEPs (pre-MMB scenario) and the scenario with MMBs because secondary bonds and MMBs seem to be the extremes of a single type of interaction with a continuous degree of strength .