hexagonal, close-packed

Elements with a hexagonal, close-packed (h.c.p.) crystalline structure include hydrogen (and deuterium, hexagonal close-packed forms), helium, (alpha form), beryllium (alpha form), nitrogen (beta form), neon (hexagonal close-packed form), magnesium, calcium (gamma form, may contain hydrogen) scandium (alpha form), titanium (alpha form) cobalt (beta form), zinc, strontium (beta form), yttrium (alpha form), zirconium (alpha form), technetium, ruthenium, cadmium, antimony (metal form), lanthanum (alpha form), praseodymium (alpha form), neodymium (alpha form), samarium (high pressure form),gadolinium (alpha form), terbium (alpha form), dysprosium (alpha form), holmium (alpha form), erbium (alpha form), thulium, lutetium (alpha form), hafnium (alpha form), rhenium, osmium, americium (alpha form), curium (alpha form), berkelium (alpha form), californium (alpha form), and einsteinium (alpha form).