Hydroxylapatite
Hughes J M, Cameron M, Mariano A N
American Mineralogist 76 (1991) 1165-1173
Rare-earth-element ordering and structural variations in natural
rare-earth-bearing apatites
sample B from the Oka carbonatite
_database_code_amcsd 0001375
9.4202 9.4202 6.9157 90 90 120 P6_3/m
atom      x      y     z  occ  Biso
Ca1     2/3    1/3 .0004 .939 1.101
Na1     2/3    1/3 .0004 .010 1.101
Ce1     2/3    1/3 .0004 .051 1.101
Ca2  .99088 .24301   .25 .893 1.000
Ce2  .99088 .24301   .25 .107 1.000
P    .36896 .39824   .25 .865   .73
Si   .36896 .39824   .25 .135   .73
O1    .4842  .3261   .25       1.08
O2    .4659  .5874   .25       1.35
O3    .2567  .3421 .0708       1.72
F         0      0   .25 .335   1.9
OH        0      0  .304 .332   2.3