Neptunium-beta Wyckoff R W G Crystal Structures 1 (1963) 7-83 Second edition. Interscience Publishers, New York, New York Sample is stable between 551 K and 843 K Note: T = 586 K _database_code_amcsd 0011264 4.897 4.897 3.388 90 90 90 P42_12 atom x y z Np1 0 0 0 Np2 0 .5 -.375