data_global _chemical_name_mineral 'Davidsmithite' loop_ _publ_author_name 'Rossi G' 'Oberti R' 'Smith D C' _journal_name_full 'European Journal of Mineralogy' _journal_volume 1 _journal_year 1989 _journal_page_first 59 _journal_page_last 70 _publ_section_title ; The crystal structure of a K-poor Ca-rich silicate with the nepheline framework, and crystal-chemical relationships in the compositional space (K,Na,Ca,_)8(Al,Si)16O32 Sample: G201b7 ; _database_code_amcsd 0006340 _chemical_formula_sum 'Na3.33 Ca.285 K.1 Al4 Si4 O16' _cell_length_a 9.982 _cell_length_b 9.982 _cell_length_c 8.364 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 721.738 _exptl_crystal_density_diffrn 2.614 _symmetry_space_group_name_H-M 'P 63' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x-y,x,1/2+z' '-y,x-y,z' '-x,-y,1/2+z' '-x+y,-x,z' 'y,-x+y,1/2+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 Na 0.99450 0.44230 0.99020 0.98000 0.02153 Ca 0.00000 0.00000 0.98540 0.03500 0.05953 Na 0.00000 0.00000 0.98540 0.38000 0.05953 K 0.00000 0.00000 0.98540 0.10000 0.05953 Ca* 0.00000 0.00000 0.83580 0.25000 0.12918 Na* 0.00000 0.00000 0.83580 0.01000 0.12918 AlT1 0.33333 0.66667 0.18050 1.00000 0.02533 SiT2 0.33333 0.66667 0.79510 1.00000 0.01140 SiT3 0.09260 0.33250 0.30280 1.00000 0.01646 AlT4 0.09550 0.33430 0.67680 1.00000 0.01900 O1 0.33240 0.71280 0.97270 0.33333 0.04939 O2 0.02980 0.32000 0.48860 1.00000 0.04813 O3 0.17550 0.52560 0.71960 1.00000 0.03673 O4 0.16200 0.50670 0.22970 1.00000 0.04053 O5 0.22810 0.28680 0.29900 1.00000 0.02786 O6 0.22330 0.26860 0.68250 1.00000 0.03166 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 Na 0.02385 0.01893 0.01737 0.00757 0.00110 -0.01392 Ca 0.06020 0.06020 0.05741 0.02991 0.00000 0.00000 Na 0.06020 0.06020 0.05741 0.02991 0.00000 0.00000 K 0.06020 0.06020 0.05741 0.02991 0.00000 0.00000 Ca' 0.01969 0.01969 0.34767 0.00984 0.00000 0.00000 Na' 0.01969 0.01969 0.34767 0.00984 0.00000 0.00000 AlT1 0.02877 0.02877 0.02020 0.01439 0.00000 0.00000 SiT2 0.01060 0.01060 0.01347 0.00568 0.00000 0.00000 SiT3 0.01514 0.00151 0.02800 0.00076 0.00806 0.00586 AlT4 0.01022 0.04051 0.01382 0.01666 0.00549 0.00769 O1 0.08897 0.05830 0.01347 0.04543 -0.00110 -0.01868 O2 0.03294 0.11168 0.02020 0.05225 -0.00220 -0.00623 O3 0.01174 0.01590 0.08258 0.00644 -0.00256 0.01172 O4 0.02612 0.00719 0.08187 0.00416 -0.01429 0.00073 O5 0.01211 0.02612 0.03863 0.00379 -0.00916 -0.01099 O6 0.04884 0.05717 0.01878 0.04732 -0.01172 -0.01538