data_global
_chemical_name_mineral 'Hillebrandite'
loop_
_publ_author_name
'Dai Y S'
'Post J E'
_journal_name_full 'American Mineralogist'
_journal_volume 80 
_journal_year 1995
_journal_page_first 841
_journal_page_last 844
_publ_section_title
;
 Crystal structure of hillebrandite: A natural analogue of calcium silicate
 hydrate (CSH) phases in Portland cement
;
_database_code_amcsd 0001745
_chemical_formula_sum 'Ca3 Si1.5 O7.5 H2'
_cell_length_a 3.6389
_cell_length_b 16.311
_cell_length_c 11.829
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 702.100
_exptl_crystal_density_diffrn      2.690
_symmetry_space_group_name_H-M 'C m c 21'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,z'
  '1/2-x,1/2+y,z'
  '-x,-y,1/2+z'
  '1/2-x,1/2-y,1/2+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
Ca1   0.00000   0.21640   0.06400   1.00000   0.01370
Ca2   0.50000   0.39920  -0.04790   1.00000   0.01140
Ca3   0.50000   0.04900   0.18880   1.00000   0.01180
Si1   0.43000   0.08630  -0.10190   0.50000   0.01100
Si2   0.50000   0.37270   0.21340   0.50000   0.00800
O-H1   0.00000   0.30910  -0.08120   1.00000   0.01400
O2   0.50000   0.12590   0.01980   1.00000   0.01300
O3   0.50000   0.46370   0.13800   1.00000   0.02400
O4   0.50000   0.29640   0.12510   1.00000   0.01900
O5   0.00000   0.48900  -0.11230   1.00000   0.01000
O-H6   0.00000   0.13700   0.23610   1.00000   0.01300
O7   0.36400   0.13280  -0.20500   0.50000   0.01400
O8   0.00000   0.11000  -0.12700   0.50000   0.01400