data_global _amcsd_formula_title 'MgMnSiO4' loop_ _publ_author_name 'Redfern S A T' 'Henderson C M B' 'Knight K S' 'Wood B J' _journal_name_full 'European Journal of Mineralogy' _journal_volume 9 _journal_year 1997 _journal_page_first 287 _journal_page_last 300 _publ_section_title ; High-temperature order-disorder in (Fe0.5Mn0.5)2SiO4 and (Mg0.5Mn0.5)2SiO4 olivines: an in situ neutron diffraction study Sample: T = 800 C ; _database_code_amcsd 0006689 _chemical_formula_sum '(Mg Mn) Si O4' _cell_length_a 4.8657 _cell_length_b 10.5893 _cell_length_c 6.2066 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 319.791 _exptl_crystal_density_diffrn 3.558 _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 MgM1 0.00000 0.00000 0.00000 0.68100 0.03800 MnM1 0.00000 0.00000 0.00000 0.31900 0.03800 MnM2 0.98700 0.25720 0.25000 0.68100 0.03800 MgM2 0.98700 0.25720 0.25000 0.31900 0.03800 Si 0.42350 0.09350 0.25000 1.00000 0.02026 O1 0.75930 0.09140 0.25000 1.00000 0.03103 O2 0.22110 0.45190 0.25000 1.00000 0.03052 O3 0.28400 0.16290 0.03930 1.00000 0.03331