Columbite-(Fe) Wenger M, Armbruster T, Geiger C A American Mineralogist 76 (1991) 1897-1904 Cation distribution in partially ordered columbite from the Kings Mountain pegmatite, North Carolina SAMPLE ncp1, T = 293 K _database_code_amcsd 0001436 14.221 5.727 5.102 90 90 90 Pbcn atom x y z occ Biso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) NbA 0 .3327 .25 .271 1.25 0.0090 0.0115 0.0105 0 0.001 0 TaA 0 .3327 .25 .091 1.25 0.0090 0.0115 0.0105 0 0.001 0 FeA 0 .3327 .25 .638 1.25 0.0090 0.0115 0.0105 0 0.001 0 NbB .16391 .1725 .7462 .614 .49 0.0049 0.0076 0.0062 -.0002 .0000 0.001 TaB .16391 .1725 .7462 .205 .49 0.0049 0.0076 0.0062 -.0002 .0000 0.001 FeB .16391 .1725 .7462 .181 .49 0.0049 0.0076 0.0062 -.0002 .0000 0.001 O1 .0941 .107 .072 0.7 O2 .4211 .117 .090 0.4 O3 .7577 .120 .082 0.6