data_global _chemical_name_mineral 'Tephroite' loop_ _publ_author_name 'Yamazaki S' 'Toraya H' _journal_name_full 'Journal of Applied Crystallography' _journal_volume 32 _journal_year 1999 _journal_page_first 51 _journal_page_last 59 _publ_section_title ; Rietveld refinement of site-occupancy parameters of Mg2-xMnxSiO4 using a new weight function in least-squares fitting Note: e = 1 ; _database_code_amcsd 0019692 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Mn2 Si O4' _cell_length_a 10.60016 _cell_length_b 6.25753 _cell_length_c 4.90338 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 325.245 _exptl_crystal_density_diffrn 4.124 _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 MnM1 0.00000 0.00000 0.00000 0.01292 MnM2 0.27990 0.25000 0.98750 0.01178 Si 0.09680 0.25000 0.42780 0.00937 O1 0.09200 0.25000 0.75270 0.01292 O2 0.45700 0.25000 0.21310 0.01013 O3 0.16210 0.04690 0.28650 0.01507