data_global _chemical_name_mineral 'Forsterite' loop_ _publ_author_name 'Takeuchi Y' 'Yamanaka T' 'Haga N' 'Hirano M' _journal_name_full 'Materials Science of the Earth's Interior' _journal_volume 1984 _journal_year 1984 _journal_page_first 191 _journal_page_last 231 _publ_section_title ; High-temperature crystallography of olivines and spinels Note: T = 25 C ; _database_code_amcsd 0014393 _chemical_formula_sum 'Mg2 Si O4' _cell_length_a 4.7503 _cell_length_b 10.187 _cell_length_c 5.9771 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 289.240 _exptl_crystal_density_diffrn 3.231 _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_U_iso_or_equiv Mg1 0.00000 0.00000 0.00000 0.00671 Mg2 0.99160 0.27750 0.25000 0.00671 Si 0.42660 0.09413 0.25000 0.00469 O1 0.76640 0.09140 0.25000 0.00659 O2 0.22150 0.44720 0.25000 0.00621 O3 0.27780 0.16310 0.03320 0.00684 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Mg1 0.00720 0.00862 0.00452 -0.00034 -0.00058 -0.00102 Mg2 0.00800 0.00647 0.00579 0.00015 0.00000 0.00000 Si 0.00480 0.00557 0.00380 0.00010 0.00000 0.00000 O1 0.00537 0.00888 0.00543 0.00025 0.00000 0.00000 O2 0.00732 0.00594 0.00543 0.00025 0.00000 0.00000 O3 0.00754 0.00810 0.00471 0.00000 -0.00029 -0.00126