data_global _chemical_name_mineral 'Pekovite' loop_ _publ_author_name 'Pautov L A' 'Agakhanov A A' 'Sokolova E V' 'Hawthorne F C' _journal_name_full 'The Canadian Mineralogist' _journal_volume 42 _journal_year 2004 _journal_page_first 107 _journal_page_last 119 _publ_section_title ; Maleevite, BaB2Si2O8, and pekovite, SrB2Si2O8, new mineral species from the Dara-i-Pioz alkaline massif, Northern Tajikistan: Description and crystal structure ; _database_code_amcsd 0005929 _chemical_compound_source 'Dara-i-Pioz alkaline massif, Northern Tajikistan' _chemical_formula_sum 'Sr B2 Si2 O8' _cell_length_a 8.155 _cell_length_b 7.919 _cell_length_c 8.921 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 576.113 _exptl_crystal_density_diffrn 3.383 _symmetry_space_group_name_H-M 'P n m a' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-x,1/2+y,-z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' '1/2+x,y,1/2-z' '1/2-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_U_iso_or_equiv SrA 0.38756 0.25000 0.07841 0.00898 BT1 0.26500 0.08080 0.41530 0.00490 SiT2 0.06105 0.94094 0.19163 0.00500 O1 0.20020 0.98330 0.06880 0.00850 O2 0.13440 0.96370 0.35970 0.00710 O3 0.41030 0.07250 0.32070 0.00750 O4 0.49240 0.75000 0.32770 0.00770 O5 0.19510 0.25000 0.41270 0.00860 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 SrA 0.01290 0.00370 0.01030 0.00000 -0.00050 0.00000 BT1 0.00830 0.00000 0.00630 -0.00070 0.00070 -0.00060 SiT2 0.00820 0.00060 0.00610 -0.00020 -0.00010 -0.00020 O1 0.01370 0.00470 0.00710 -0.00330 0.00210 -0.00180 O2 0.01140 0.00440 0.00550 -0.00170 -0.00120 -0.00020 O3 0.01130 0.00070 0.01060 0.00150 0.00330 -0.00050 O4 0.01270 0.00010 0.01000 0.00000 0.00190 0.00000 O5 0.00780 0.00460 0.01300 0.00000 0.00260 0.00000