data_global _chemical_name_mineral 'Ilvaite' loop_ _publ_author_name 'Ghose S' 'Hewat A W' 'Marezio M' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 11 _journal_year 1984 _journal_page_first 67 _journal_page_last 74 _publ_section_title ; A neutron powder diffraction study of the crystal and magnetic structures of ilvaite from 305 K to 5 K - a mixed valence iron silicate with an electronic transition Sample: T = 5 K ; _database_code_amcsd 0007361 _chemical_formula_sum 'Ca Fe2.925 Mn.075 Si2 O9 H' _cell_length_a 13.0229 _cell_length_b 8.7977 _cell_length_c 5.8428 _cell_angle_alpha 90 _cell_angle_beta 90.234 _cell_angle_gamma 90 _cell_volume 669.413 _exptl_crystal_density_diffrn 4.056 _symmetry_space_group_name_H-M 'P 1 21/a 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,z' '1/2-x,1/2+y,-z' '-x,-y,-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 Ca 0.81340 0.37050 0.73130 1.00000 0.02406 FeM11 0.88900 0.05540 0.01010 1.00000 0.00608 FeM12 0.88960 0.04700 0.49440 1.00000 0.00608 FeM2 0.94100 0.74380 0.24160 0.92500 0.00798 MnM2 0.94100 0.74380 0.24160 0.07500 0.00798 Si1 0.96490 0.36810 0.22230 1.00000 0.00709 Si2 0.67920 0.22910 0.25610 1.00000 0.00709 O1 0.01020 0.02850 0.73390 1.00000 0.01140 O21 0.93790 0.27310 0.01110 1.00000 0.01140 O22 0.93390 0.27250 0.48530 1.00000 0.01140 O5 0.58570 0.10300 0.26070 1.00000 0.01140 O6 0.60040 0.02600 0.75260 1.00000 0.01140 O3 0.77840 0.10860 0.26390 1.00000 0.01140 O41 0.66700 0.32800 0.01590 1.00000 0.01140 O42 0.67160 0.33680 0.47900 1.00000 0.01140 O7 0.79770 0.10510 0.73810 1.00000 0.01140 H 0.73360 0.06100 0.73860 1.00000 0.01874