Calcite Markgraf S A, Reeder R J American Mineralogist 70 (1985) 590-600 High-temperature structure refinements of calcite and magnesite Sample: T = 200 C _database_code_amcsd 0000985 4.984 4.984 17.121 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 .0171 .0171 .00111 .00855 0 0 C 0 0 .25 .0159 .0159 .00101 .00795 0 0 O .2562 0 .25 .0195 .0376 .00221 .0188 -.00165 -.0033