data_global _chemical_name_mineral 'Mascagnite' loop_ _publ_author_name 'Schlemper E O' 'Hamilton W C' _journal_name_full 'Journal of Chemical Physics' _journal_volume 44 _journal_year 1966 _journal_page_first 4498 _journal_page_last 4509 _publ_section_title ; Neutron-diffraction study of the structures of ferroelectric and paraelectric ammonium sulfate Note: ferroelectric, T = 180 K ; _database_code_amcsd 0012987 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'N2 H8 S O4' _cell_length_a 7.837 _cell_length_b 10.61 _cell_length_c 5.967 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 496.159 _exptl_crystal_density_diffrn 1.769 _symmetry_space_group_name_H-M 'P n a 21' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,z' '1/2-x,1/2+y,1/2+z' '-x,-y,1/2+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z N1 0.68080 0.39580 0.24500 N2 0.97960 0.69990 0.25600 H1 0.77100 0.33600 0.20200 H2 0.56400 0.36000 0.20600 H3 0.69100 0.48000 0.15700 H4 0.68200 0.41200 0.40800 H5 0.09200 0.65800 0.22200 H6 0.99000 0.79300 0.26500 H7 0.89600 0.67000 0.14200 H8 0.94500 0.67200 0.41200 S 0.24300 0.42100 0.25000 O1 0.06100 0.40200 0.21200 O2 0.28400 0.55700 0.22200 O3 0.33900 0.34600 0.08300 O4 0.29400 0.38200 0.47700 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 N1 0.02930 0.00800 0.02240 -0.00460 -0.00360 0.00670 N2 0.02460 0.00570 0.02560 0.00040 -0.00880 0.00480 H1 0.10300 0.03650 0.07320 0.03750 0.04790 0.00450 H2 0.04290 0.04620 0.05860 -0.01100 -0.00730 0.00710 H3 0.04980 0.01540 0.03100 0.00930 0.01900 0.02980 H4 0.03420 0.05360 0.04830 0.00420 0.01020 -0.01570 H5 0.04610 0.07080 0.02560 0.02530 0.00920 0.02410 H6 0.09210 0.00860 0.07610 0.00670 -0.03010 -0.02250 H7 0.06540 0.03600 0.05610 -0.01390 -0.03080 0.01700 H8 0.02610 0.06390 0.04580 -0.00460 -0.00400 0.01090 S 0.02210 0.00910 0.03070 0.00040 -0.00210 -0.00190 O1 0.01650 0.02800 0.02650 -0.00460 -0.00540 -0.00060 O2 0.02650 0.00800 0.02450 -0.00590 0.00330 -0.00290 O3 0.02860 0.01370 0.02310 0.00210 0.00900 0.00130 O4 0.02770 0.01310 0.01770 0.00040 -0.00210 0.00190