data_global _amcsd_formula_title 'Pb21[Si7O22]2[Si4O13]' loop_ _publ_author_name 'Siidra O I' 'Zenko D S' 'Krivovichev S V' _journal_name_full 'American Mineralogist' _journal_volume 99 _journal_year 2014 _journal_page_first 817 _journal_page_last 823 _publ_section_title ; Structural complexity of lead silicates: Crystal structure of Pb21[Si7O22]2[Si4O13] and its comparison to hyttsjoite ; _database_code_amcsd 0020132 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Pb21 Si18 O57' _cell_length_a 9.9244 _cell_length_b 9.9244 _cell_length_c 34.2357 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 2920.239 _exptl_crystal_density_diffrn 6.561 _symmetry_space_group_name_H-M 'P 63/m' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x+y,-x,1/2-z' 'x-y,x,1/2+z' 'y,-x+y,-z' '-y,x-y,z' 'x,y,1/2-z' '-x,-y,1/2+z' 'x-y,x,-z' '-x+y,-x,z' '-y,x-y,1/2-z' 'y,-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 Pb1 0.66667 0.33333 0.59498 1.00000 0.01184 Pb2 0.66667 0.33333 0.49065 1.00000 0.01352 Pb3 0.75175 0.01367 0.54549 1.00000 0.01375 Pb4 0.08035 0.64380 0.65363 1.00000 0.01664 Pb5 0.66667 0.33333 0.69810 1.00000 0.02069 Pb6 0.82080 0.76030 0.75000 0.33333 0.01220 Pb6A 0.80130 0.75630 0.74109 0.33333 0.04810 Si1 0.00000 0.00000 0.66788 1.00000 0.02060 Si2 0.98730 0.57070 0.75000 1.00000 0.01180 Si3 0.60290 0.60770 0.55296 1.00000 0.01010 Si4 0.93600 0.24920 0.63335 1.00000 0.01340 Si5 0.33333 0.66667 0.73980 0.50000 0.00850 O1 0.85530 0.38550 0.75000 1.00000 0.01250 O2 0.69550 0.51350 0.54715 1.00000 0.01370 O3 0.64460 0.73440 0.51870 1.00000 0.01910 O4 0.75990 0.12520 0.62150 1.00000 0.02130 O5 0.03890 0.33150 0.59424 1.00000 0.02240 O6 0.00000 0.00000 0.71410 1.00000 0.02200 O7 0.96380 0.65420 0.71210 1.00000 0.02450 O8 0.14120 0.97620 0.65320 1.00000 0.03010 O9 0.41740 0.49430 0.55690 1.00000 0.02840 O10 0.94420 0.38210 0.66170 1.00000 0.03700 O11 0.15810 0.58310 0.75000 1.00000 0.04800 O12 0.33333 0.66667 0.69430 0.50000 0.02700 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 Pb1 0.01273 0.01273 0.01010 0.00637 0.00000 0.00000 Pb2 0.01453 0.01453 0.01150 0.00726 0.00000 0.00000 Pb3 0.01206 0.01489 0.01423 0.00668 -0.00022 0.00059 Pb4 0.01375 0.01605 0.01811 0.00594 0.00214 0.00081 Pb5 0.02583 0.02583 0.01040 0.01292 0.00000 0.00000 Pb6 0.00610 0.01200 0.01810 0.00420 0.00000 0.00000 Pb6A 0.04440 0.04810 0.06600 0.03350 0.03210 0.02580 Si1 0.01950 0.01950 0.02300 0.00980 0.00000 0.00000 Si2 0.00930 0.01030 0.01450 0.00400 0.00000 0.00000 Si3 0.01150 0.01080 0.00900 0.00620 -0.00190 0.00050 Si4 0.01310 0.01480 0.01040 0.00560 0.00000 0.00090 Si5 0.00710 0.00710 0.01100 0.00360 0.00000 0.00000 O1 0.01500 0.01300 0.01000 0.00800 0.00000 0.00000 O2 0.01700 0.01200 0.01300 0.00700 0.00100 -0.00200 O3 0.03100 0.01700 0.01500 0.01600 0.00300 0.00500 O4 0.00900 0.02600 0.02400 0.00500 0.00500 0.00800 O5 0.01200 0.03300 0.01200 0.00300 0.00100 0.01100 O6 0.02100 0.02100 0.02400 0.01050 0.00000 0.00000 O7 0.03700 0.02800 0.01700 0.02300 0.01200 0.00900 O8 0.02600 0.02700 0.04200 0.01600 0.01600 0.00600 O9 0.01100 0.01400 0.05800 0.00500 -0.00200 -0.00400 O10 0.03200 0.02100 0.04200 0.00200 0.01600 -0.01300 O11 0.00500 0.01500 0.11900 0.00100 0.00000 0.00000