Crookesite Eriksson L, Werner P E, Berger R, Meerschaut A Journal of Solid State Chemistry 90 (1991) 61-68 Structure refinement of TlCu7Se4 from X-ray powder profile data Locality: synthetic Sample: STADI/P Note: Cell parameters are an average of Table 1 values _database_code_amcsd 0013692 10.4500 10.4500 3.9708 90 90 90 I4/m atom x y z occ Tl 0 0 0 Cu1 .0197 .3703 0 Cu2 .325 .2210 0 .75 Se .2441 .4336 0