data_global _chemical_name_mineral 'Pezzottaite' loop_ _publ_author_name 'Yakubivich O V' 'Pekov I V' 'Steele I M' 'Massa W' 'Chukanov N V' _journal_name_full 'Crystallography Reports' _journal_volume 54 _journal_year 2009 _journal_page_first 399 _journal_page_last 412 _publ_section_title ; Alkali metals in beryl and their role in the formation of derivative structural motifs: Comparative crystal chemistry of vorobyevite and pezzottaite Note: T = 100 K ; _database_code_amcsd 0012413 _chemical_compound_source 'Sakavalana granitic pegmatite, Antsirabe, Fianarantsoa Province, Madagascar' _chemical_formula_sum 'Cs.75 Na.226 Al2 Be2 Li Si6 O18.285 H.57' _cell_length_a 15.955 _cell_length_b 15.955 _cell_length_c 27.810 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 6130.914 _exptl_crystal_density_diffrn 3.146 _symmetry_space_group_name_H-M 'R -3 c' loop_ _space_group_symop_operation_xyz 'x,y,z' '2/3+x,1/3+y,1/3+z' '1/3+x,2/3+y,2/3+z' 'x,x-y,1/2+z' '2/3+x,1/3+x-y,5/6+z' '1/3+x,2/3+x-y,1/6+z' 'y,x,1/2-z' '2/3+y,1/3+x,5/6-z' '1/3+y,2/3+x,1/6-z' '-x+y,y,1/2+z' '2/3-x+y,1/3+y,5/6+z' '1/3-x+y,2/3+y,1/6+z' '-x,-x+y,1/2-z' '2/3-x,1/3-x+y,5/6-z' '1/3-x,2/3-x+y,1/6-z' '-y,-x,1/2+z' '2/3-y,1/3-x,5/6+z' '1/3-y,2/3-x,1/6+z' 'x-y,-y,1/2-z' '2/3+x-y,1/3-y,5/6-z' '1/3+x-y,2/3-y,1/6-z' 'y,-x+y,-z' '2/3+y,1/3-x+y,1/3-z' '1/3+y,2/3-x+y,2/3-z' '-x+y,-x,z' '2/3-x+y,1/3-x,1/3+z' '1/3-x+y,2/3-x,2/3+z' '-x,-y,-z' '2/3-x,1/3-y,1/3-z' '1/3-x,2/3-y,2/3-z' '-y,x-y,z' '2/3-y,1/3+x-y,1/3+z' '1/3-y,2/3+x-y,2/3+z' 'x-y,x,-z' '2/3+x-y,1/3+x,1/3-z' '1/3+x-y,2/3+x,2/3-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 Cs1 0.00000 0.00000 0.08211 0.72500 0.01090 Cs2 0.00000 0.00000 0.25000 0.79900 0.01470 Na1 0.00000 0.00000 0.00000 0.27500 0.01600 Na2 0.00000 0.00000 0.16420 0.20100 0.05400 Al1 0.66667 0.00060 0.08333 1.00000 0.00510 Al2 -0.00537 0.33333 0.08333 1.00000 0.00480 Be 0.33790 0.17040 0.08405 1.00000 0.00920 Li 0.50290 0.50290 0.75000 1.00000 ? Si1 0.04514 0.21958 -0.00087 1.00000 0.00470 Si2 0.21996 0.05024 0.16537 1.00000 0.00430 Si3 0.04988 -0.17024 0.16640 1.00000 0.00430 O1 0.27630 0.06410 0.21529 1.00000 0.00930 O2 0.07000 0.28070 -0.05057 1.00000 0.00940 O3 0.06060 -0.22840 0.12294 1.00000 0.01320 O4 0.28880 0.07380 0.11915 1.00000 0.00880 O5 0.05220 0.28240 0.04492 1.00000 0.01270 O6 0.06800 -0.20480 0.21771 1.00000 0.00970 O7 -0.05870 0.12010 -0.00490 1.00000 0.01040 O8 -0.05340 -0.17360 0.16590 1.00000 0.00930 O9 0.12650 -0.05610 0.16022 1.00000 0.01120 Wat10 -0.03800 -0.03800 0.25000 0.07100 0.10000 Wat11 0.02600 0.00300 0.08400 0.10700 0.09900