data_global _chemical_name_mineral 'Kosmochlor' loop_ _publ_author_name 'Origlieri M J' 'Downs R T' 'Thompson R M' 'Pommier C J S' 'Denton M B' 'Harlow G E' _journal_name_full 'American Mineralogist' _journal_volume 88 _journal_year 2003 _journal_page_first 1025 _journal_page_last 1032 _publ_section_title ; High-pressure crystal structure of kosmochlor, NaCrSi2O6, and systematics of anisotropic compression in pyroxenes Sample: P = 0.0001 GPa Note: altered y-coordinate of O2 ; _database_code_amcsd 0003133 _chemical_formula_sum 'Na Cr Si2 O6' _cell_length_a 9.5720 _cell_length_b 8.7094 _cell_length_c 5.2678 _cell_angle_alpha 90 _cell_angle_beta 107.498 _cell_angle_gamma 90 _cell_volume 418.836 _exptl_crystal_density_diffrn 3.602 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Na2 0.00000 0.29990 0.25000 0.01963 Cr1 0.00000 0.90769 0.25000 0.01153 Si 0.29259 0.09180 0.23430 0.01165 O1 0.11370 0.07840 0.13660 0.01279 O2 0.36050 0.25890 0.30330 0.01583 O3 0.35290 0.00950 0.00920 0.01444 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 Na2 0.02153 0.01729 0.01560 0.00000 -0.00116 0.00000 Cr1 0.01170 0.01153 0.00997 0.00000 0.00116 0.00000 Si 0.01182 0.01191 0.01036 0.00000 0.00186 0.00000 O1 0.01140 0.01460 0.01036 -0.00081 0.00093 0.00089 O2 0.01604 0.01499 0.01573 -0.00201 0.00325 -0.00022 O3 0.01478 0.01537 0.01240 0.00242 0.00325 -0.00044