data_global _chemical_name_mineral 'Melilite' loop_ _publ_author_name 'Armbruster T' 'Rothlisberger F' 'Seifert F' _journal_name_full 'American Mineralogist' _journal_volume 75 _journal_year 1990 _journal_page_first 847 _journal_page_last 858 _publ_section_title ; Layer topology, stacking variation and site distortion in melilite-related compounds in the system CaO-ZnO-GeO2-SiO2 low-temperature polymorph Ca2ZnGe1.25Si.75O7 ; _database_code_amcsd 0001316 _chemical_formula_sum 'Zn (Ge1.255 Si.745) Ca2 O7' _cell_length_a 9.112 _cell_length_b 7.900 _cell_length_c 9.380 _cell_angle_alpha 90 _cell_angle_beta 114.03 _cell_angle_gamma 90 _cell_volume 616.698 _exptl_crystal_density_diffrn 3.981 _symmetry_space_group_name_H-M 'P 1 21/n 1' loop_ _space_group_symop_operation_xyz 'x,y,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_occupancy Zn1 0.82867 0.09678 0.11477 1.00000 Ge2 0.87207 0.45559 0.20899 0.73400 Si2 0.87207 0.45559 0.20899 0.26600 Ge3 0.96891 0.76878 0.07667 0.52100 Si3 0.96891 0.76878 0.07667 0.47900 Ca4 0.45740 0.28210 0.02820 1.00000 Ca5 0.28910 0.56540 0.20140 1.00000 O1 0.00940 0.56820 0.15720 1.00000 O2 0.63210 0.06250 0.13430 1.00000 O3 0.69150 0.45570 0.05010 1.00000 O4 0.96720 -0.09870 0.21910 1.00000 O5 0.85640 0.18100 -0.06510 1.00000 O6 0.95450 0.26250 0.27640 1.00000 O7 0.29590 0.72920 0.42070 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 Zn1 0.00810 0.01010 0.01000 0.00010 0.00440 0.00100 Ge2 0.00610 0.00610 0.00610 0.00000 0.00250 0.00000 Si2 0.00610 0.00610 0.00610 0.00000 0.00250 0.00000 Ge3 0.00590 0.00590 0.00590 0.00000 0.00240 0.00000 Si3 0.00590 0.00590 0.00590 0.00000 0.00240 0.00000 Ca4 0.00870 0.01070 0.00710 0.00240 0.00260 0.00060 Ca5 0.01200 0.02440 0.00920 0.01000 0.00430 0.00140 O1 0.01020 0.01150 0.01370 0.00090 0.00530 0.00240 O2 0.01040 0.01790 0.01420 0.00300 0.00710 0.00810 O3 0.00860 0.01120 0.00840 -0.00010 0.00330 0.00050 O4 0.01160 0.00850 0.00770 0.00160 0.00350 0.00010 O5 0.01200 0.01640 0.01030 0.00140 0.00550 0.00440 O6 0.01450 0.01170 0.00730 -0.00230 0.00090 -0.00050 O7 0.01220 0.01860 0.01340 -0.00100 0.00470 -0.00390