data_global _chemical_name_mineral 'Tephroite' loop_ _publ_author_name 'Redfern S A T' 'Knight K S' 'Henderson C M B' 'Wood B J' _journal_name_full 'Mineralogical Magazine' _journal_volume 62 _journal_year 1998 _journal_page_first 607 _journal_page_last 615 _publ_section_title ; Fe-Mn cation ordering in fayalite-tephroite (FexMn1-x)2SiO4 olivines: A neutron diffraction study ; _database_code_amcsd 0019696 _chemical_compound_source 'Synthetic' _chemical_formula_sum '(Mn1.4 Fe.6) Si O4' _cell_length_a 4.87890 _cell_length_b 10.60587 _cell_length_c 6.20468 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 321.061 _exptl_crystal_density_diffrn 4.189 _symmetry_space_group_name_H-M 'P b n 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_occupancy _atom_site_U_iso_or_equiv MnM1 0.00000 0.00000 0.00000 0.54600 0.00456 FeM1 0.00000 0.00000 0.00000 0.45400 0.00456 MnM2 0.99540 0.27930 0.25000 0.85400 0.00684 FeM2 0.99540 0.27930 0.25000 0.14600 0.00684 Si 0.42850 0.09600 0.25000 1.00000 0.00494 O1 0.76060 0.09260 0.25000 1.00000 0.00861 O2 0.21260 0.45360 0.25000 1.00000 0.00785 O3 0.28710 0.16370 0.03950 1.00000 0.00735