Calcite Althoff P L American Mineralogist 62 (1977) 772-783 Structural refinements of dolomite and a magnesian calcite and implications for dolomite formation in the marine environment Mg-calcite _database_code_amcsd 0000585 4.941 4.941 16.864 90 90 120 R-3c atom x y z occ B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Ca 0 0 0 .9 .0249 .0249 .00153 .01245 0 0 Mg 0 0 0 .1 .0020 .002 .0002 .001 0 0 C 0 0 .25 .0178 .0178 .0013 .0089 0 0 O .2583 0 .25 .027 .049 .0028 .0245 -.0013 -.0026