Helium Schuch A F, Mills R L Physical Review Letters 8 (1962) 469-470 Structure of the gamma form of solid He4 Locality: synthetic Sample: at T = 1.73 K & P = .003 GPa _database_code_amcsd 0015274 3.650 3.650 5.945 90 90 120 P6_3/mmc atom x y z He 1/3 2/3 .25