data_global _chemical_name_mineral 'Afwillite' loop_ _publ_author_name 'Megaw H D' _journal_name_full 'Acta Crystallographica' _journal_volume 5 _journal_year 1952 _journal_page_first 477 _journal_page_last 491 _publ_section_title ; The structure of afwillite, Ca3(SiO3OH)2*2H2O ; _database_code_amcsd 0009147 _chemical_compound_source 'Scawt Hill, Northern Ireland' _chemical_formula_sum 'Ca3 Si2 O10 H6' _cell_length_a 16.27 _cell_length_b 5.632 _cell_length_c 13.23 _cell_angle_alpha 90 _cell_angle_beta 134.80 _cell_angle_gamma 90 _cell_volume 860.212 _exptl_crystal_density_diffrn 2.644 _symmetry_space_group_name_H-M 'C 1 c 1' 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' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Ca1 0.19680 0.03480 0.29200 0.01773 Ca2 0.80120 0.04850 0.20930 0.01773 Ca3 0.50370 0.03620 0.02880 0.01773 Si1 0.11750 0.04420 0.00070 0.01773 Si2 0.86920 0.97530 0.99820 0.01773 O1 0.99180 0.91520 0.34100 0.01773 O-H2 0.99920 0.90450 0.15380 0.01773 O3 0.78370 0.96950 0.02070 0.01773 O-H4 0.21580 0.05450 0.98880 0.01773 O5 0.33120 0.73520 0.39050 0.01773 O6 0.36300 0.28200 0.43330 0.01773 O7 0.14730 0.26670 0.09830 0.01773 O8 0.13180 0.81250 0.07780 0.01773 Wat9 0.56300 0.97950 0.25830 0.01773 Wat10 0.41200 0.96930 0.26470 0.01773