data_global _chemical_name_mineral 'Forsterite' loop_ _publ_author_name 'Henderson C M B' 'Redfern S A T' 'Smith R I' 'Knight K S' 'Charnock J M' _journal_name_full 'American Mineralogist' _journal_volume 86 _journal_year 2001 _journal_page_first 1170 _journal_page_last 1187 _publ_section_title ; Composition and temperature dependence of cation ordering in Ni-Mg olivine solid solutions: A time-of-flight neutron powder diffraction and EXAFS study Sample: Mg70Ni30 at room temperature ; _database_code_amcsd 0002677 _chemical_formula_sum '(Ni.6 Mg1.4) Si O4' _cell_length_a 4.7460 _cell_length_b 10.194 _cell_length_c 5.9568 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 288.194 _exptl_crystal_density_diffrn 3.718 _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 0.49500 0.00494 Mg1 0.00000 0.00000 0.00000 0.50500 0.00494 Ni2 0.99080 0.27630 0.25000 0.10500 0.00557 Mg2 0.99080 0.27630 0.25000 0.89500 0.00557 Si 0.42550 0.09360 0.25000 1.00000 0.00317 O1 0.76750 0.09280 0.25000 1.00000 0.00519 O2 0.22060 0.44630 0.25000 1.00000 0.00557 O3 0.27600 0.16270 0.03240 1.00000 0.00545