Regarding ERMBs and EDMBs, it must be considered that the large ET value in the studied molecules with ERMBs is indicative of the strong charge difference between the central and the external atoms of the linear 3c-4e bonds, in which external atoms have much larger negative charges than the central atom . On the other hand, the low ES value (0.6) in B2H6, which has two B-H-B 3c-2e bonds can be understood if each 3c-2e bond is considered as the result of two resonant or interacting 2c-1e bonds, as already commented by Lipscomb and coworkers . This consideration is similar to that of Wuttig and coworkers, who consider MMBs as 2c-1e bonds but without considering its multicenter character .