data_global _chemical_name_mineral 'Plancheite' loop_ _publ_author_name 'Evans H T' 'Mrose M E' _journal_name_full 'American Mineralogist' _journal_volume 62 _journal_year 1977 _journal_page_first 491 _journal_page_last 502 _publ_section_title ; The crystal chemistry of the hydrous copper silicates, shattuckite and plancheite Note: sample is from Rioja, Argentina ; _database_code_amcsd 0000579 _chemical_formula_sum 'Cu8 Si8 O27 H6' _cell_length_a 19.043 _cell_length_b 20.129 _cell_length_c 5.269 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 2019.695 _exptl_crystal_density_diffrn 3.851 _symmetry_space_group_name_H-M 'P c n b' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2+y,-z' '-x,1/2-y,z' '1/2-x,y,1/2+z' '1/2+x,-y,1/2-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 Cu1 0.45920 0.01000 0.26900 0.00177 Cu2 0.37460 0.03290 0.79100 0.00177 Cu3 0.29250 0.05630 0.31700 0.00177 Cu4 0.25180 0.30850 0.71300 0.00241 Si1 0.64080 0.10710 0.94100 0.00152 Si2 0.56350 0.12390 0.42200 0.00152 Si3 0.40730 0.16370 0.50500 0.00152 Si4 0.33230 0.18730 0.99700 0.00152 O1 0.62900 0.02800 0.94200 0.00177 O2 0.54500 0.04700 0.49600 0.00139 O3 0.38200 0.08700 0.50400 0.00165 O4 0.30200 0.11200 0.95500 0.00152 O5 0.72400 0.12600 0.94000 0.00215 O6 0.59900 0.14400 0.17300 0.00127 O7 0.62000 0.14000 0.66500 0.00101 O8 0.49300 0.16500 0.48500 0.00127 O9 0.38600 0.19500 0.76900 0.00101 O10 0.37300 0.20400 0.26800 0.00177 O11 0.27200 0.24600 0.98500 0.00139 O-H12 0.46200 0.06200 0.98100 0.00190 O-H13 0.28700 0.00500 0.58100 0.00203 Wat14 0.50000 0.25000 0.95000 0.00253