The Hexagonal Close Packed (HCP) structure is a type of crystallographic arrangement found in many materials, particularly metals. In this arrangement, atoms are packed together as closely as possible, forming a repeating hexagonal pattern. Each atom has 12 nearest neighbors: six in the same plane, three in the plane above, and three in the plane below. This dense packing results in high stability and is a common structure in nanomaterials due to its efficient use of space.
