Calcite Markgraf S A, Reeder R J American Mineralogist 70 (1985) 590-600 High-temperature structure refinements of calcite and magnesite Sample: T = 800 C Note: B33 of Ca has been altered from the reported value _database_code_amcsd 0000989 4.976 4.976 17.488 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 .0512 .0512 .00299 .0256 0 0 C 0 0 .25 .039 .039 .0032 .0195 0 0 O .2530 0 .25 .063 .131 .0061 .0655 -.00565 -.0113