It is significant that the occurrence of EDMBs under compression, as in the Ah and Ai phases of group-15 and -16 elements, in atomic/polymeric nitrogen and hydrogen, and, in general, in all materials at elevated pressures, agrees with the general view that all elements, irrespective of their valence electrons, should show EDMBs at HP . Note that pressure tends to increase atomic coordination and all elements and compounds will fall short in electrons to share with neighbor atoms at a certain pressure, i.e. above a given atomic coordination . Therefore, all the new bonds in hypercoordinated atoms will have to share necessarily less than two electrons per atomic pair until full electron delocalization, typical of metallic bonding, is finally attained at even higher pressures.