Apophyllite-(KF) Stahl K European Journal of Mineralogy 5 (1993) 845-849 A neutron powder diffraction study of partially dehydrated fluorapophyllite, KCa4Si8O20F*6.9H2O _database_code_amcsd 0006492 8.9639 8.9639 15.754 90 90 90 P4/mnc atom x y z occ F 0 0 0 K 0 0 1/2 Ca .1150 .2402 0 Si .2317 .0873 .1917 O1 .3624 .1376 1/4 O2 .0894 .1915 .2159 O3 .2663 .1021 .0923 O4 .2132 .4489 .0903 .69 O5 .1848 .4878 0 .34 H1 .4465 .1722 .0894 .69 H2 .2209 .4257 .1492 .69 H3 .1574 .5505 .0366 .34