data_global _chemical_name_mineral 'Enstatite' loop_ _publ_author_name 'Yang H' 'Ghose S' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 22 _journal_year 1995 _journal_page_first 300 _journal_page_last 310 _publ_section_title ; High temperature single crystal X-ray diffraction studies of the ortho-proto phase transition in enstatite, Mg2Si2O6 at 1360 K Sample: T = 1200 K ; _database_code_amcsd 0007921 _chemical_formula_sum 'Mg Si O3' _cell_length_a 18.413 _cell_length_b 8.929 _cell_length_c 5.246 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 862.493 _exptl_crystal_density_diffrn 3.092 _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_U_iso_or_equiv Mg1 0.37530 0.65140 0.87800 0.02227 Mg2 0.37620 0.48760 0.37250 0.03189 SiA 0.27200 0.34030 0.05900 0.01553 SiB 0.47490 0.33800 0.78950 0.01538 O1A 0.18440 0.33960 0.04840 0.02196 O1B 0.56290 0.34200 0.79150 0.02156 O2A 0.31090 0.49920 0.05720 0.02601 O2B 0.43370 0.48470 0.69740 0.02596 O3A 0.30250 0.22730 -0.16600 0.02623 O3B 0.44900 0.20370 0.58750 0.02661 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 0.02405 0.02464 0.01799 0.00000 -0.00294 0.00024 Mg2 0.03779 0.03231 0.02551 -0.00416 -0.01077 0.00427 SiA 0.01546 0.01737 0.01352 -0.00250 0.00000 -0.00071 SiB 0.01374 0.01777 0.01422 0.00167 -0.00147 0.00047 O1A 0.01889 0.02625 0.02008 0.00083 0.00000 0.00095 O1B 0.01718 0.02787 0.02022 0.00083 -0.00147 0.00047 O2A 0.02748 0.02262 0.02747 -0.00916 -0.00294 0.00308 O2B 0.02920 0.02585 0.02370 0.00833 -0.00147 0.00570 O3A 0.02061 0.03837 0.01994 0.00167 -0.00147 -0.01092 O3B 0.02405 0.03312 0.02217 -0.00250 -0.00049 -0.01020