Each ion of sodium is surrounded by 6 chlorine ions and each ion of chlorine is surrounded by 6 sodium ions. Correspondingly, each ion of chlorine is surrounded by eight ions of cesium. Its unit cell has atoms of carbon at opposing corners of a cube and one carbon atom in the center of the cube. Soot and charcoal are other forms of carbon which are composed of very small crystals of graphite. As a result, metallic solids permit electrons to move freely through the solid.
Metals can be bent and shaped without breaking.
Nonmetal crystals are brittle and cannot be worked. This is the principal reason that metals were valued in antiquity. The reason that metals have this property is that they are actually composed of very small crystals that are weakly bonded to each other. It is easy to slide these crystals by each other. Alternately, you can look at the ductility in terms of dislocations at crystal boundaries that reduce the force needed to deform that metals.