data_global _amcsd_formula_title 'NH4Cr(SO4)2*12H2O' loop_ _publ_author_name 'Rempfer N' 'Lerner H W' 'Bolte M' _journal_name_full 'Acta Crystallographica, Section E' _journal_volume 60 _journal_year 2004 _journal_page_first i80 _journal_page_last i81 _publ_section_title ; The ammonium chromium(III) alum NH4Cr(SO4)2*12H2O ; _database_code_amcsd 0010434 _chemical_formula_sum 'N H28 Cr S2 O20' _cell_length_a 12.2491 _cell_length_b 12.2491 _cell_length_c 12.2491 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1837.860 _exptl_crystal_density_diffrn 1.729 _symmetry_space_group_name_H-M 'P a 3' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+z,x,1/2-y' 'z,1/2-x,1/2+y' '1/2-z,1/2+x,y' '-z,-x,-y' '1/2+y,1/2-z,-x' '1/2-y,-z,1/2+x' '-y,1/2+z,1/2-x' 'y,z,x' 'x,1/2-y,1/2+z' '1/2-x,1/2+y,z' '1/2+x,y,1/2-z' '-x,-y,-z' '1/2-z,-x,1/2+y' '-z,1/2+x,1/2-y' '1/2+z,1/2-x,-y' 'z,x,y' '1/2-y,1/2+z,x' '1/2+y,z,1/2-x' 'y,1/2-z,1/2+x' '-y,-z,-x' '-x,1/2+y,1/2-z' '1/2+x,1/2-y,-z' '1/2-x,-y,1/2+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 N 0.00000 0.50000 0.50000 1.00000 0.03230 H1 0.01200 0.54400 0.55300 0.66667 0.03900 Cr 0.50000 0.50000 0.50000 1.00000 0.00994 S 0.80864 0.69136 0.30864 1.00000 0.01273 O1 0.81058 0.73618 0.41998 1.00000 0.02520 O2 0.73931 0.76069 0.23931 1.00000 0.03400 O3 0.48764 0.51483 0.34114 1.00000 0.01480 H3A 0.47080 0.57120 0.31310 1.00000 0.03500 H3B 0.48030 0.46260 0.29830 1.00000 0.03600 O4 0.04676 0.63817 0.69723 1.00000 0.02200 H4A 0.00750 0.68290 0.70820 1.00000 0.02600 H4B 0.10400 0.66630 0.70850 1.00000 0.03900 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 N 0.03230 0.03230 0.03230 -0.01600 0.01600 -0.01600 Cr 0.00994 0.00994 0.00994 -0.00036 -0.00036 -0.00036 S 0.01273 0.01273 0.01273 -0.00183 0.00183 -0.00183 O1 0.02190 0.03480 0.01900 -0.01110 0.00420 -0.01260 O2 0.03400 0.03400 0.03400 0.00850 -0.00850 0.00850 O3 0.01970 0.01340 0.01140 0.00130 -0.00160 -0.00030 O4 0.02050 0.01880 0.02660 0.00380 0.00600 0.00580