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 (high) Model 2, T = 433 K Locality: synthetic _database_code_amcsd 0019149 5.787 5.787 5.787 90 90 90 Fm3m atom x y z occ Uiso Cu1 .25 .25 .25 .47 .057 Cu2 .315 .315 .315 .12 .083 Cu3 .5 0 0 .05 .177 Se 0 0 0 .045