data_global _amcsd_formula_title 'K2Mg3Cu2Si12O30' loop_ _publ_author_name 'Nguyen N' 'Choisnet J' 'Raveau B' _journal_name_full 'Journal of Solid State Chemistry' _journal_volume 34 _journal_year 1980 _journal_page_first 1 _journal_page_last 9 _publ_section_title ; Silicates synthetiques a structure milarite ; _database_code_amcsd 0013388 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'K2 (Mg3 Cu2) Si12 O30' _cell_length_a 10.169 _cell_length_b 10.169 _cell_length_c 14.182 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 1270.061 _exptl_crystal_density_diffrn 2.864 _symmetry_space_group_name_H-M 'P 6/m c c' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-x+y,1/2+z' 'x,x-y,1/2-z' '-x+y,-x,-z' 'x-y,x,z' '-y,-x,1/2+z' 'y,x,1/2-z' 'y,-x+y,-z' '-y,x-y,z' 'x-y,-y,1/2+z' '-x+y,y,1/2-z' 'x,y,-z' '-x,-y,z' 'x,x-y,1/2+z' '-x,-x+y,1/2-z' 'x-y,x,-z' '-x+y,-x,z' 'y,x,1/2+z' '-y,-x,1/2-z' '-y,x-y,-z' 'y,-x+y,z' '-x+y,y,1/2+z' 'x-y,-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 KA1 0.00000 0.00000 0.25000 1.00000 0.01646 KA2 0.33333 0.66667 0.00000 0.50000 0.01140 MgM1 0.33333 0.66667 0.25000 0.87500 0.02786 CuM1 0.33333 0.66667 0.25000 0.12500 0.02786 MgM2 0.50000 0.00000 0.25000 0.41670 0.02026 CuM2 0.50000 0.00000 0.25000 0.58330 0.02026 Si 0.76400 0.11000 0.11000 1.00000 0.00507 O1 0.74700 0.13100 0.00000 1.00000 0.01773 O2 0.93100 0.21200 0.14000 1.00000 0.00127 O3 0.66200 0.15700 0.16500 1.00000 0.00380