noun
hexagonal close packing
Technical term in geology and crystallography for the arrangement of atoms or particles in a hexagonal close-packed structure.
六方最密充填は、結晶構造の一つとして地質学でよく扱われる。
Hexagonal close packing is often discussed in geology as one of the crystal structures.
Compound of 六方 (hexagonal), 最密 (closest packing), and 充填 (filling). The exact historical derivation is uncertain; the term is a modern technical coinage.