data_global _chemical_name_mineral 'Enstatite' loop_ _publ_author_name 'Hugh-Jones D A' 'Chopelas A' 'Angel R J' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 24 _journal_year 1997 _journal_page_first 301 _journal_page_last 310 _publ_section_title ; Tetrahedral compression in (Mg,Fe)SiO3 orthopyroxenes Sample: P = 6.59 GPa, synthetic En60 orthopyroxene ; _database_code_amcsd 0008016 _chemical_formula_sum '(Mg.59 Fe.41) Si O3' _cell_length_a 18.0665 _cell_length_b 8.706 _cell_length_c 5.1236 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 805.875 _exptl_crystal_density_diffrn 3.736 _symmetry_space_group_name_H-M 'P b c a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,1/2+z' '-x,1/2+y,1/2-z' '1/2-x,1/2+y,z' '1/2+x,1/2-y,-z' '1/2+x,y,1/2-z' '1/2-x,-y,1/2+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 0.37630 0.65760 0.86120 0.59000 0.00076 FeM1 0.37630 0.65760 0.86120 0.41000 0.00076 MgM2 0.37830 0.48020 0.35440 0.59000 0.00076 FeM2 0.37830 0.48020 0.35440 0.41000 0.00076 SiTA 0.27120 0.34130 0.03930 1.00000 0.00013 SiTB 0.47290 0.33770 0.80100 1.00000 0.00025 O1a 0.18270 0.34000 0.02800 1.00000 0.00063 O2a 0.30910 0.50600 0.04000 1.00000 0.00127 O3a 0.30430 0.23000 0.81500 1.00000 0.00089 O1b 0.56140 0.33900 0.80600 1.00000 0.00076 O2b 0.43370 0.48500 0.68700 1.00000 0.00089 O3b 0.44540 0.19400 0.60800 1.00000 0.00304