Calcite Markgraf S A, Reeder R J American Mineralogist 70 (1985) 590-600 High-temperature structure refinements of calcite and magnesite Sample: T = 24 C _database_code_amcsd 0000984 4.988 4.988 17.061 90 90 120 R-3c atom x y z B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Ca 0 0 0 .0122 .0122 .00085 .0061 0 0 C 0 0 .25 .012 .012 .0008 .006 0 0 O .2567 0 .25 .0142 .0256 .00159 .0128 -.0011 -.0022