data_global _amcsd_formula_title 'BCTT' loop_ _publ_author_name 'Dollase W A' 'Ross C R' _journal_name_full 'American Mineralogist' _journal_volume 78 _journal_year 1993 _journal_page_first 627 _journal_page_last 632 _publ_section_title ; Crystal structures of the body-centered tetragonal tectosilicates: K1.14Mg0.57Si1.43O4, K1.10Zn0.55Si1.45O4, and K1.11Fe1.11Si0.89O4 Sample: Mg-rich phase ; _database_code_amcsd 0001571 _chemical_formula_sum 'K2.28 (Mg1.14 Si2.86) O8' _cell_length_a 8.957 _cell_length_b 8.957 _cell_length_c 5.281 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 423.683 _exptl_crystal_density_diffrn 2.549 _symmetry_space_group_name_H-M 'I 4 m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '-y,-x,z' '1/2-y,1/2-x,1/2+z' '-y,x,z' '1/2-y,1/2+x,1/2+z' 'x,-y,z' '1/2+x,1/2-y,1/2+z' '-x,-y,z' '1/2-x,1/2-y,1/2+z' 'y,x,z' '1/2+y,1/2+x,1/2+z' 'y,-x,z' '1/2+y,1/2-x,1/2+z' '-x,y,z' '1/2-x,1/2+y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy K1 0.00000 0.50000 0.29600 0.64000 K2 0.00000 0.00000 0.49790 1.00000 Mg 0.18050 0.18050 0.00000 0.28500 Si 0.18050 0.18050 0.00000 0.71500 O1 0.21440 0.00000 0.06950 1.00000 O2 0.28890 0.28890 0.19140 1.00000 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 K1 0.02439 0.06909 0.46625 0.00000 0.00000 0.00000 K2 0.04471 0.04471 0.03250 0.00000 0.00000 0.00000 Mg 0.03252 0.03252 0.02967 -0.00406 0.00479 0.00479 Si 0.03252 0.03252 0.02967 -0.00406 0.00479 0.00479 O1 0.10974 0.04471 0.07347 0.00000 0.02157 0.00000 O2 0.10161 0.10161 0.05510 -0.06097 0.02157 0.02157