Hydroxylapatite Wilson R M, Elliot J C, Dowker S E P American Mineralogist 84 (1999) 1406-1414 Rietveld refinement of the crystallographic structure of human dental enamel apatites Sample: RC8 - enamel _database_code_amcsd 0002287 9.4343 9.4343 6.8681 90 90 120 P6_3/m atom x y z occ Ca1 2/3 1/3 .0024 .97 Na1 2/3 1/3 .0024 .02 Mg1 2/3 1/3 .0024 .01 Ca2 .2442 .9880 .25 .92 Na2 .2442 .9880 .25 .02 Mg2 .2442 .9880 .25 .01 P .3975 .3668 .25 .87 O1 .3254 .4863 .25 .91 O2 .5684 .4542 .25 O3 .3445 .2604 .0697 .94 Oh 0 0 .1747 .57 H 0 0 .0608 .23