Berzelianite Yamamoto K, Kashida S Journal of Solid State Chemistry 93 (1991) 202-211 X-ray study of the average structures of Cu2Se and Cu1.8S in the room temperature and the high temperature phases Note: Sample: Cu2Se (low), T = 300 K Locality: synthetic _database_code_amcsd 0019147 5.694 5.694 5.694 90 90 90 Fm3m atom x y z occ Uiso Cu1 .25 .25 .25 .36 .068 Cu2 .334 .334 .334 .16 .085 Se 0 0 0 .39