data_global _chemical_name_mineral 'Ilvaite' loop_ _publ_author_name 'Ghose S' 'Tsukimura K' 'Hatch D M' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 16 _journal_year 1989 _journal_page_first 483 _journal_page_last 496 _publ_section_title ; Phase transitions in ilvaite, a mixed-valence iron silicate II. A single-crystal X-ray diffraction study and Landau theory of the monoclinic to orthorhombic phase transition induced by charge delocalization Sample: T = 380 K ; _database_code_amcsd 0007457 _chemical_formula_sum 'Fe3 Ca Si2 O9 H' _cell_length_a 13.05330 _cell_length_b 8.83450 _cell_length_c 5.86740 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 676.625 _exptl_crystal_density_diffrn 4.013 _symmetry_space_group_name_H-M 'P n a m' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,y,1/2-z' '-x,-y,1/2+z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-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_U_iso_or_equiv FeAo 0.89027 0.05075 0.00665 0.00890 FeB 0.94035 0.73943 0.25000 0.00950 Ca 0.81299 0.37056 0.75000 0.00970 Si1 0.95958 0.36809 0.25000 0.00630 Si2 0.67942 0.22704 0.25000 0.00630 O1 0.01020 0.02930 0.75000 0.01310 O2o 0.93631 0.27187 0.01664 0.00910 O3 0.77705 0.10968 0.25000 0.00940 O4o 0.67107 0.32947 0.01850 0.00980 O5 0.58481 0.10132 0.25000 0.00890 O6 0.60190 0.02427 0.75000 0.01270 O-H7 0.79761 0.10879 0.75000 0.00880 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 FeAo 0.00870 0.00870 0.00940 -0.00010 -0.00070 0.00080 FeB 0.01060 0.00860 0.00950 -0.00060 0.00000 0.00000 Ca 0.00890 0.00820 0.01210 0.00070 0.00000 0.00000 Si1 0.00680 0.00670 0.00550 0.00010 0.00000 0.00000 Si2 0.00670 0.00680 0.00570 0.00060 0.00000 0.00000 O1 0.01370 0.01120 0.01440 0.00030 0.00000 0.00000 O2o 0.01040 0.00980 0.00720 -0.00130 -0.00010 -0.00170 O3 0.00970 0.00880 0.00970 0.00110 0.00000 0.00000 O4o 0.01070 0.01080 0.00800 0.00010 0.00040 0.00160 O5 0.00830 0.00910 0.00950 0.00050 0.00000 0.00000 O6 0.01160 0.00890 0.01770 -0.00290 0.00000 0.00000 O-H7 0.00900 0.00940 0.00810 0.00150 0.00000 0.00000