hexagonal close-packed

Hexagonal close-packed (HCP) is a highly efficient way atoms arrange themselves in certain metals. Imagine stacking layers of circles so each circle fits snugly into the gaps of the layer below, forming a pattern similar to a honeycomb. In HCP, atoms are arranged in a repeating pattern where each atom touches 12 neighbors, creating a dense, stable structure with hexagonal symmetry. This arrangement maximizes packing efficiency, leaving minimal empty space, which contributes to the metal's strength and ductility. Common examples of metals with HCP structure include magnesium, titanium, and cobalt.