Moreover, by working with elemental solids exhibiting pure covalent bonds, we show that EDMB can occur between purely covalent and metallic bonds. This is in contrast to a previous claim that considered that the formation of multicenter bonds could only occur between ionic and metallic bonds . It can be concluded that EDMB is an unconventional bond characterized by a mixture of localized electrons between two atoms and delocalized electrons over more than two atoms. This means that EDMBs can be considered as 2c-1e bonds that are characterized by ES ≈ 1; i.e. half the value expected for a pure covalent bond. In conclusion, the EDMB is a directional bond intermediate between ionocovalent p-type bonds (with fully localized electrons) and metallic bonds (with fully delocalized electrons), where the number of electrons shared between two atoms is around one instead of two as in ionocovalent bonds.