data_global _chemical_name_mineral 'Forsterite' 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 0019684 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Mg2 Si O4' _cell_length_a 10.20141 _cell_length_b 5.98348 _cell_length_c 4.75534 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 290.266 _exptl_crystal_density_diffrn 3.219 _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 MgM1 0.00000 0.00000 0.00000 0.01343 MgM2 0.27720 0.25000 0.99140 0.01279 Si 0.09370 0.25000 0.42600 0.01127 O1 0.09090 0.25000 0.76270 0.01127 O2 0.44940 0.25000 0.22040 0.01305 O3 0.16150 0.03660 0.27820 0.01431