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: RE2 - enamel _database_code_amcsd 0002289 9.4598 9.4598 6.8865 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 .2452 .9905 .25 .93 Na2 .2452 .9905 .25 .02 P .3977 .3696 .25 .93 O1 .3327 .4875 .25 .89 O2 .5779 .4602 .25 O3 .3364 .2532 .0716 .85 Oh 0 0 .1881 .48 H 0 0 .0608 .79