data_global _chemical_name_mineral 'Fayalite' loop_ _publ_author_name 'Lottermoser W' 'Steiner K' 'Grodzicki M' 'Jiang K' 'Scharfetter G' 'Bats J W' 'Redhammer G J' 'Treutmann W' 'Hosoya S' 'Amthauer G' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 29 _journal_year 2002 _journal_page_first 112 _journal_page_last 121 _publ_section_title ; The electric field gradient in synthetic fayalite alpha-Fe2SiO4 at moderate temperatures Sample: T = 153 K ; _database_code_amcsd 0008631 _chemical_formula_sum 'Fe2 Si O4' _cell_length_a 10.4597 _cell_length_b 6.0818 _cell_length_c 4.8150 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 306.300 _exptl_crystal_density_diffrn 4.419 _symmetry_space_group_name_H-M 'P n m a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-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 Fe1 0.00000 0.00000 0.00000 0.00420 Fe2 0.28003 0.25000 0.98599 0.00400 Si 0.09745 0.25000 0.43085 0.00350 O1 0.09174 0.25000 0.76800 0.00510 O2 -0.04688 0.25000 0.29110 0.00490 O3 0.16580 0.03601 0.28842 0.00530 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 Fe1 0.00530 0.00350 0.00380 -0.00080 0.00010 -0.00030 Fe2 0.00390 0.00320 0.00500 0.00000 0.00000 0.00000 Si 0.00380 0.00310 0.00370 0.00000 0.00020 0.00000 O1 0.00600 0.00500 0.00420 0.00000 0.00030 0.00000 O2 0.00400 0.00500 0.00570 0.00000 -0.00010 0.00000 O3 0.00620 0.00390 0.00590 0.00100 0.00020 -0.00040