For metallic structures, does the packing efficiency (see sample exercise 12.1 in textbook) increase or decrease as the number of nearest neighbors (the coordination number) decreases?
Metallic solids or metallic structures experience metallic bonds which are the forces of attractions between the sea of electrons and the nucleus of the metallic atoms. They share a network of highly delocalized electrons. I therefore think that the packing efficiency decreases as the number of nearest neighbors decreases.
