data_global _chemical_name_mineral 'Forsterite' loop_ _publ_author_name 'Ottonello G' 'Della Giusta A' 'Molin G M' _journal_name_full 'American Mineralogist' _journal_volume 74 _journal_year 1989 _journal_page_first 411 _journal_page_last 421 _publ_section_title ; Cation ordering in Ni-Mg olivines sample Ni.30A, heated to 800 C, then quenched Mg1.4Ni.6SiO4 ; _database_code_amcsd 0001220 _chemical_formula_sum '(Ni.597 Mg1.403) Si O4' _cell_length_a 4.7459 _cell_length_b 10.1950 _cell_length_c 5.9559 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 288.173 _exptl_crystal_density_diffrn 3.716 _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 Ni1 0.00000 0.00000 0.00000 0.50800 0.00823 Mg1 0.00000 0.00000 0.00000 0.49200 0.00823 Ni2 0.99060 0.27600 0.25000 0.08900 0.00887 Mg2 0.99060 0.27600 0.25000 0.91100 0.01001 Si 0.42610 0.09360 0.25000 1.00000 0.00747 O1 0.76670 0.09270 0.25000 1.00000 0.00836 O2 0.22100 0.44620 0.25000 1.00000 0.00899 O3 0.27600 0.16280 0.03210 1.00000 0.00925