data_global _chemical_name_mineral 'Neptunite' loop_ _publ_author_name 'Kunz M' 'Armbruster T' 'Lager G A' 'Schultz A J' 'Goyette R J' 'Lottermoser W' 'Amthauer G' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 18 _journal_year 1991 _journal_page_first 199 _journal_page_last 213 _publ_section_title ; Fe, Ti ordering and octahedral distortions in acentric neptunite: temperature dependent X-ray and neutron structure refinements and Mossbauer Spectroscopy Sample: T = 110 K ; _database_code_amcsd 0007531 _chemical_compound_source 'San Benito, California, USA' _chemical_formula_sum 'Na2 K Li Ti2 Fe2 Si8 O24' _cell_length_a 16.430 _cell_length_b 12.436 _cell_length_c 9.963 _cell_angle_alpha 90 _cell_angle_beta 115.60 _cell_angle_gamma 90 _cell_volume 1835.838 _exptl_crystal_density_diffrn 3.286 _symmetry_space_group_name_H-M 'C 1 c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+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 Na1 0.26710 0.19690 0.31230 Na2 -0.26030 -0.19940 -0.30010 K1 0.00000 0.42191 0.25000 Li1 0.50300 0.43540 0.25300 Ti1 0.34190 0.32516 0.10320 Fe1 -0.33840 -0.31636 -0.09590 Ti2 0.08760 0.05251 0.11410 Fe2 -0.08860 -0.06083 -0.11160 Si1 0.14740 0.40790 0.06150 Si1a -0.14320 -0.40490 -0.05900 Si2 0.52560 0.22580 0.08540 Si2a -0.52100 -0.22840 -0.08540 Si3 0.77090 0.47270 0.10870 Si3a -0.76910 -0.47480 -0.10890 Si4 0.89610 0.15050 0.08000 Si4a -0.89390 -0.14920 -0.08400 O1 0.95910 0.05010 0.07230 O1a -0.94820 -0.04480 -0.07150 O2 0.45660 0.32470 0.07170 O2a -0.45580 -0.32920 -0.06770 O3 0.10990 0.16870 0.25880 O3a -0.10900 -0.16940 -0.26690 O4 0.37170 0.43120 0.22420 O4a -0.37440 -0.44850 -0.25780 O5 0.20630 0.07370 0.09500 O5a -0.20800 -0.07920 -0.09100 O6 0.71360 0.36330 0.04030 O6a -0.70800 -0.36730 -0.04990 O7 0.21530 0.30990 0.07860 O7a -0.20320 -0.30200 -0.06490 O8 0.83300 0.49240 0.02120 O8a -0.83060 -0.48820 -0.01700 O9 0.15910 0.44990 0.22200 O9a -0.15820 -0.44810 -0.22250 O10 0.39730 0.21240 0.25170 O10a -0.39170 -0.20890 -0.25520 O11 0.46500 0.11560 0.02710 O11a -0.45910 -0.11920 -0.02930 O12 0.92900 0.26070 0.02620 O12a -0.93040 -0.25620 -0.03510 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 Na1 0.00900 0.01120 0.01100 -0.00210 0.00570 -0.00370 Na2 0.00700 0.01080 0.00750 -0.00330 0.00340 -0.00190 K1 0.00600 0.01750 0.00900 0.00090 0.00290 0.00070 Li1 0.01100 0.00800 0.00900 -0.00700 0.00700 -0.00700 Ti1 0.00300 0.00290 0.00320 0.00000 0.00150 0.00010 Fe1 0.00390 0.00540 0.00440 -0.00260 0.00120 0.00080 Ti2 0.00220 0.00480 0.00360 0.00030 0.00080 -0.00040 Fe2 0.00430 0.00540 0.00430 -0.00100 0.00250 -0.00110 Si1 0.00290 0.00300 0.00170 -0.00020 0.00080 -0.00030 Si1a 0.00240 0.00340 0.00450 0.00000 0.00150 0.00010 Si2 0.00270 0.00270 0.00270 -0.00010 0.00070 0.00020 Si2a 0.00290 0.00300 0.00400 -0.00040 0.00160 -0.00070 Si3 0.00300 0.00290 0.00320 0.00010 0.00140 -0.00020 Si3a 0.00320 0.00370 0.00300 0.00010 0.00120 0.00070 Si4 0.00340 0.00270 0.00380 0.00030 0.00180 -0.00030 Si4a 0.00330 0.00340 0.00210 -0.00010 0.00110 0.00020 O1 0.00280 0.00590 0.00600 0.00010 0.00230 -0.00060 O1a 0.00280 0.00590 0.00600 0.00010 0.00230 -0.00060 O2 0.00490 0.00540 0.00560 0.00060 0.00250 -0.00090 O2a 0.00490 0.00540 0.00560 0.00060 0.00250 -0.00090 O3 0.00660 0.00600 0.00570 -0.00090 0.00340 -0.00010 O3a 0.00660 0.00600 0.00570 -0.00090 0.00340 -0.00010 O4 0.00600 0.00700 0.00500 0.00180 0.00200 -0.00040 O4a 0.00700 0.00700 0.00900 -0.00170 0.00400 -0.00010 O5 0.00450 0.00410 0.00570 0.00080 0.00210 0.00000 O5a 0.00450 0.00410 0.00570 0.00080 0.00210 0.00000 O6 0.00320 0.00480 0.00670 0.00010 0.00100 -0.00010 O6a 0.00320 0.00480 0.00670 0.00010 0.00100 -0.00010 O7 0.00390 0.00530 0.00580 0.00110 0.00240 -0.00040 O7a 0.00390 0.00530 0.00580 0.00110 0.00240 -0.00040 O8 0.00670 0.00430 0.00650 0.00030 0.00430 0.00080 O8a 0.00670 0.00430 0.00650 0.00030 0.00430 0.00080 O9 0.00610 0.00610 0.00390 -0.00010 0.00210 -0.00090 O9a 0.00610 0.00610 0.00390 -0.00010 0.00210 -0.00090 O10 0.00410 0.00600 0.00550 -0.00080 0.00040 0.00010 O10a 0.00410 0.00600 0.00550 -0.00080 0.00040 0.00010 O11 0.00270 0.00520 0.00660 -0.00040 0.00130 -0.00010 O11a 0.00270 0.00520 0.00660 -0.00040 0.00130 -0.00010 O12 0.00640 0.00380 0.00640 0.00030 0.00380 0.00100 O12a 0.00640 0.00380 0.00640 0.00030 0.00380 0.00100