data_global _chemical_name_mineral 'Forsterite' loop_ _publ_author_name 'Hazen R M' _journal_name_full 'American Mineralogist' _journal_volume 61 _journal_year 1976 _journal_page_first 1280 _journal_page_last 1293 _publ_section_title ; Effects of temperature and pressure on the crystal structure of forsterite T = 350 C P = 1 atm olivine ; _database_code_amcsd 0000547 _chemical_formula_sum 'Si Mg2 O4' _cell_length_a 4.763 _cell_length_b 10.24 _cell_length_c 5.999 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 292.590 _exptl_crystal_density_diffrn 3.194 _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 Si 0.42570 0.09390 0.25000 Mg1 0.00000 0.00000 0.00000 Mg2 0.99150 0.27800 0.25000 O1 0.76570 0.09100 0.25000 O2 0.21780 0.44920 0.25000 O3 0.28220 0.16190 0.03470 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 Si 0.00299 0.00531 0.00456 0.00025 0.00000 0.00000 Mg1 0.00862 0.01116 0.00529 -0.00025 -0.00072 -0.00218 Mg2 0.00931 0.00744 0.00820 0.00012 0.00000 0.00000 O1 0.01080 0.00637 0.00930 0.00074 0.00000 0.00000 O2 0.00839 0.00744 0.00729 -0.00025 0.00000 0.00000 O3 0.00942 0.00850 0.00675 -0.00074 -0.00029 0.00187