data_global _chemical_name_mineral 'Feldspar' loop_ _publ_author_name 'Grundy H D' 'Ito J' _journal_name_full 'American Mineralogist' _journal_volume 59 _journal_year 1974 _journal_page_first 1319 _journal_page_last 1326 _publ_section_title ; The refinement of the crystal structure of a synthetic non-stoichiometric Sr feldspar ; _database_code_amcsd 0000436 _chemical_formula_sum '(Si2.26 Al1.74) Sr.84 Na.03 O8' _cell_length_a 8.3282 _cell_length_b 12.9801 _cell_length_c 7.1358 _cell_angle_alpha 90 _cell_angle_beta 115.599 _cell_angle_gamma 90 _cell_volume 695.667 _exptl_crystal_density_diffrn 2.986 _symmetry_space_group_name_H-M 'C 1 2/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,z' '1/2+x,1/2-y,z' '-x,y,-z' '1/2-x,1/2+y,-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_occupancy Si1 0.00540 0.17720 0.22370 0.52000 Al1 0.00540 0.17720 0.22370 0.48000 Si2 0.69080 0.11660 0.34140 0.61000 Al2 0.69080 0.11660 0.34140 0.39000 Sr 0.26960 0.00000 0.13060 0.84000 Na 0.26960 0.00000 0.13060 0.03000 OA(1) 0.00000 0.13290 0.00000 1.00000 OA(2) 0.59510 0.00000 0.28430 1.00000 OB 0.82010 0.12980 0.22120 1.00000 OC 0.01930 0.30520 0.25180 1.00000 OD 0.19070 0.12270 0.40250 1.00000 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 Si1 0.01129 0.01041 0.00711 -0.00341 0.00480 -0.00063 Al1 0.01129 0.01041 0.00711 -0.00341 0.00480 -0.00063 Si2 0.01106 0.00794 0.00799 -0.00005 0.00323 -0.00076 Al2 0.01106 0.00794 0.00799 -0.00005 0.00323 -0.00076 Sr 0.01743 0.03440 0.02195 0.00000 0.00455 0.00000 Na 0.01743 0.03440 0.02195 0.00000 0.00455 0.00000 OA(1) 0.02112 0.01357 0.01175 0.00000 0.01016 0.00000 OA(2) 0.00920 0.00640 0.02027 0.00000 0.00042 0.00000 OB 0.02092 0.01844 0.02325 -0.00025 0.01288 0.00474 OC 0.01900 0.01451 0.02096 -0.00193 0.00857 0.00021 OD 0.01889 0.02526 0.01385 0.00035 0.00443 0.00292