data_global _chemical_name_mineral 'Esperite' loop_ _publ_author_name 'Tait K T' 'Yang H' 'Downs R T' 'Li C' 'Pinch W W' _journal_name_full 'American Mineralogist' _journal_volume 95 _journal_year 2010 _journal_page_first 699 _journal_page_last 705 _publ_section_title ; The crystal structure of esperite, with a revised chemical formula, PbCa2(ZnSiO4)3, isostructural with beryllonite ; _database_code_amcsd 0005046 _chemical_compound_source 'Franklin, New Jersey, USA' _chemical_formula_sum 'Pb Ca2 Zn3 Si3 O12' _cell_length_a 8.7889 _cell_length_b 8.2685 _cell_length_c 15.2535 _cell_angle_alpha 90 _cell_angle_beta 90.050 _cell_angle_gamma 90 _cell_volume 1108.487 _exptl_crystal_density_diffrn 4.553 _symmetry_space_group_name_H-M 'P 1 21/n 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+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 Pb 0.24576 0.05520 0.25083 0.00928 Ca1 0.73827 0.46078 0.07414 0.00779 Ca2 0.76071 0.03835 0.08855 0.00768 Zn1 0.57626 0.33526 0.24338 0.00795 Zn2 0.07422 0.33879 0.09038 0.00789 Zn3 0.09274 0.33936 0.41626 0.00797 Si1 0.91112 0.22833 0.26527 0.00588 Si2 0.43933 0.22969 0.41207 0.00581 Si3 0.39507 0.22585 0.07455 0.00596 O1 0.40950 0.22950 0.18190 0.00940 O2 0.43390 0.73660 0.29470 0.00930 O3 0.26980 0.23030 0.36610 0.00950 O4 0.76840 0.25030 0.19790 0.00870 O5 0.91250 0.24220 0.01700 0.00820 O6 0.56550 0.25410 0.03460 0.00860 O7 0.54640 0.36720 0.36780 0.00970 O8 0.27620 0.36330 0.04170 0.00990 O9 0.91470 0.36440 0.34200 0.00970 O10 0.58890 0.55190 0.18810 0.01150 O11 -0.01720 0.55450 0.10600 0.01020 O12 0.17230 0.55080 0.45320 0.01030 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 Pb 0.01076 0.00671 0.01038 0.00027 0.00008 -0.00001 Ca1 0.00820 0.00680 0.00840 -0.00060 0.00080 0.00040 Ca2 0.00950 0.00600 0.00760 -0.00060 -0.00100 0.00040 Zn1 0.00805 0.00877 0.00704 -0.00053 0.00070 -0.00056 Zn2 0.00759 0.00824 0.00786 -0.00036 0.00004 0.00054 Zn3 0.00828 0.00850 0.00713 0.00048 -0.00057 -0.00032 Si1 0.00620 0.00580 0.00570 0.00050 -0.00010 -0.00030 Si2 0.00620 0.00590 0.00530 -0.00030 0.00050 0.00000 Si3 0.00600 0.00580 0.00620 -0.00050 0.00020 0.00010 O1 0.00950 0.01210 0.00660 -0.00380 0.00050 -0.00030 O2 0.00750 0.01210 0.00830 -0.00160 0.00070 -0.00380 O3 0.00790 0.01170 0.00890 0.00230 -0.00190 -0.00380 O4 0.00800 0.01090 0.00710 0.00190 -0.00120 -0.00160 O5 0.00970 0.00960 0.00520 -0.00200 0.00040 -0.00020 O6 0.00670 0.01040 0.00880 -0.00150 0.00120 -0.00180 O7 0.01300 0.00880 0.00730 -0.00340 0.00190 0.00020 O8 0.00910 0.00870 0.01180 0.00210 0.00130 0.00410 O9 0.01070 0.00850 0.00980 0.00150 -0.00290 -0.00360 O10 0.01730 0.00630 0.01080 -0.00070 0.00330 -0.00090 O11 0.00960 0.00550 0.01560 -0.00060 0.00120 0.00040 O12 0.01230 0.00670 0.01200 0.00110 -0.00340 0.00050