data_global _chemical_name_mineral 'Poldervaartite' loop_ _publ_author_name 'Heller L' _journal_name_full 'Acta Crystallographica' _journal_volume 5 _journal_year 1952 _journal_page_first 724 _journal_page_last 728 _publ_section_title ; The structure of dicalcium silicate alpha-hydrate ; _database_code_amcsd 0009148 _chemical_compound_source 'synthetic Ca2SiO3OHOH' _chemical_formula_sum 'Ca2 Si O5' _cell_length_a 9.34 _cell_length_b 9.22 _cell_length_c 10.61 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 913.678 _exptl_crystal_density_diffrn 2.737 _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 Ca1 0.45200 0.64000 0.75400 Ca2 0.38500 0.02200 0.43000 Si1 0.75400 0.30400 0.97500 O1 0.43900 0.35800 0.66200 O2 0.59500 0.33600 0.92800 O3 0.80900 0.17400 0.88600 O4 0.86500 0.43400 0.96600 O5 0.73900 0.27100 0.12400