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 = 850 C ; _database_code_amcsd 0006690 _chemical_formula_sum '(Mg Mn) Si O4' _cell_length_a 4.8592 _cell_length_b 10.5772 _cell_length_c 6.1988 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 318.598 _exptl_crystal_density_diffrn 3.572 _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 0.66500 0.02533 MnM1 0.00000 0.00000 0.00000 0.33500 0.02533 MnM2 0.98500 0.26820 0.25000 0.66500 0.02533 MgM2 0.98500 0.26820 0.25000 0.33500 0.02533 Si 0.42400 0.09410 0.25000 1.00000 0.01887 O1 0.75930 0.09100 0.25000 1.00000 0.02660 O2 0.22260 0.45140 0.25000 1.00000 0.02723 O3 0.28410 0.16250 0.03830 1.00000 0.02837