data_global
_chemical_name_mineral 'Poldervaartite'
loop_
_publ_author_name
'Marsh R E'
_journal_name_full 'Acta Crystallographica, Section C'
_journal_volume 50 
_journal_year 1994
_journal_page_first 996
_journal_page_last 997
_publ_section_title
;
 A revised structure for alpha-dicalcium silicate hydrate
;
_database_code_amcsd 0010292
_chemical_compound_source 'synthetic Ca2SiO3OHOH'
_chemical_formula_sum 'Ca2 Si O5 H2'
_cell_length_a 9.487
_cell_length_b 9.179
_cell_length_c 10.666
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 928.808
_exptl_crystal_density_diffrn      2.721
_symmetry_space_group_name_H-M 'P b c a'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '1/2+x,y,1/2-z'
  '1/2-x,-y,1/2+z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Ca1   0.48415   0.16956   0.06863 ?
Ca2   0.34570   0.00578   0.38878 ?
Si1   0.16927   0.21286   0.15970 ?
O1   0.05605   0.13832   0.06504 ?
O2   0.24927   0.34579   0.07281 ?
O3   0.29582   0.09944   0.19042 ?
O4   0.10182   0.29231   0.27970 ?
O5   0.39398   0.45254   0.39616 ?
H1   0.23800   0.43800   0.11000   0.04700
H2   0.40600   0.41300   0.33900   0.06200
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Ca1 0.00920 0.00860 0.00790 -0.00270 -0.00140 0.00020
Ca2 0.00770 0.00810 0.00780 -0.00030 -0.00030 0.00040
Si1 0.00670 0.00710 0.00630 -0.00040 -0.00020 -0.00010
O1 0.00840 0.00890 0.00820 -0.00170 -0.00080 -0.00090
O2 0.01690 0.00880 0.01090 -0.00120 0.00390 0.00030
O3 0.00980 0.01000 0.01200 0.00210 -0.00180 0.00090
O4 0.01410 0.01010 0.00660 -0.00200 0.00210 0.00050
O5 0.00900 0.00920 0.01100 0.00120 -0.00060 0.00060