data_global
_chemical_name_mineral 'Merrillite'
loop_
_publ_author_name
'Hughes J M'
'Jolliff B L'
'Rakovan J'
_journal_name_full 'American Mineralogist'
_journal_volume 93 
_journal_year 2008
_journal_page_first 1300
_journal_page_last 1305
_publ_section_title
;
 The crystal chemistry of whitlockite and merrillite and the
 dehydrogenation of whitlockite to merrillite
 Note: Formed through dehydrogenation of synthetic whitlockite
 by heating at 1050 degrees C for 24 hours
;
_database_code_amcsd 0004626
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Ca9.443 (Mg.935 Fe.065) P6.964 O28'
_cell_length_a 10.3499
_cell_length_b 10.3499
_cell_length_c 37.115
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 3443.122
_exptl_crystal_density_diffrn      3.092
_symmetry_space_group_name_H-M 'R 3 c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'x,x-y,1/2+z'
  '2/3+x,1/3+x-y,5/6+z'
  '1/3+x,2/3+x-y,1/6+z'
  '-y,-x,1/2+z'
  '2/3-y,1/3-x,5/6+z'
  '1/3-y,2/3-x,1/6+z'
  '-x+y,y,1/2+z'
  '2/3-x+y,1/3+y,5/6+z'
  '1/3-x+y,2/3+y,1/6+z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
CaIIB1   0.27347   0.14232   0.56805   1.00000   0.00999
CaIIB2   0.38364   0.17687   0.76923   1.00000   0.01083
CaIB   0.27226   0.14701   0.67506   1.00000   0.01981
CaIIA*   0.00000   0.00000   0.81260   0.44300   0.01470
Mg   0.00000   0.00000   0.00000   0.93500   0.00860
Fe   0.00000   0.00000   0.00000   0.06500   0.00860
PB1   0.31343   0.13900   0.86563   1.00000   0.00944
PB2   0.34384   0.15160   0.96931   1.00000   0.00837
OIB1   0.26151   0.08320   0.82711   1.00000   0.02100
OIIB1   0.24269   0.22849   0.87966   1.00000   0.01820
OIIB3   0.27624  -0.00043   0.88827   1.00000   0.01140
OIIB5   0.48536   0.24023   0.86822   1.00000   0.01480
OIIB2   0.39666   0.04391   0.95679   1.00000   0.01400
OIIB4   0.41985   0.30068   0.94937   1.00000   0.01630
OIIB6   0.17435   0.07693   0.96245   1.00000   0.01120
OIB2   0.37816   0.18167   0.00954   1.00000   0.01300
PA*   0.00000   0.00000   0.73451   0.96400   0.00920
OIA*   0.00000   0.00000   0.69336   1.00000   0.01690
OIIA*  -0.00408   0.13809   0.74822   1.00000   0.02240