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 = 4.76 GPa, synthetic En60 orthopyroxene ; _database_code_amcsd 0008014 _chemical_formula_sum '(Mg.59 Fe.41) Si O3' _cell_length_a 18.124 _cell_length_b 8.754 _cell_length_c 5.144 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 816.134 _exptl_crystal_density_diffrn 3.689 _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 0.37610 0.65700 0.86260 0.59000 0.00595 FeM1 0.37610 0.65700 0.86260 0.41000 0.00595 MgM2 0.37820 0.48130 0.35700 0.59000 0.00697 FeM2 0.37820 0.48130 0.35700 0.41000 0.00697 SiTA 0.27100 0.34190 0.04240 1.00000 0.00621 SiTB 0.47310 0.33630 0.80000 1.00000 0.00405 O1a 0.18300 0.34000 0.03100 1.00000 0.00342 O2a 0.30850 0.50900 0.03800 1.00000 0.00874 O3a 0.30230 0.23000 0.81300 1.00000 0.00025 O1b 0.56190 0.33700 0.80100 1.00000 0.00861 O2b 0.43300 0.48600 0.68800 1.00000 0.00025 O3b 0.44580 0.19500 0.60500 1.00000 0.00013