Na.33K.67MgF3 Chakhmouradian A R, Ross K, Mitchell R H, Swainson I Physics and Chemistry of Minerals 28 (2001) 277-284 The crystal chemistry of synthetic potassium-bearing neighborite, (Na1-xKx)MgF3 Sample x = .67 _database_code_amcsd 0008547 3.9622 3.9622 3.9622 90 90 90 Pm3m atom x y z occ Na .5 .5 .5 .33 K .5 .5 .5 .67 Mg 0 0 0 F .5 0 0