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 = 493 K ; _database_code_amcsd 0007533 _chemical_compound_source 'San Benito, California, USA' _chemical_formula_sum 'Na2 K Li Ti2 Fe2 Si8 O24' _cell_length_a 16.426 _cell_length_b 12.532 _cell_length_c 9.995 _cell_angle_alpha 90 _cell_angle_beta 115.51 _cell_angle_gamma 90 _cell_volume 1856.894 _exptl_crystal_density_diffrn 3.248 _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 0.26580 0.19560 0.31460 Na2 -0.26280 -0.19830 -0.30340 K1 0.00000 0.41880 0.25000 Li1 0.50000 0.43660 0.26000 Ti1 0.34160 0.32480 0.10270 Fe1 -0.33820 -0.31600 -0.09690 Ti2 0.08750 0.05240 0.11430 Fe2 -0.08840 -0.06130 -0.11250 Si1 0.14570 0.40720 0.06030 Si1a -0.14470 -0.40460 -0.05950 Si2 0.52390 0.22580 0.08420 Si2a -0.52190 -0.22970 -0.08560 Si3 0.76980 0.47330 0.10870 Si3a -0.77110 -0.47640 -0.11060 Si4 0.89440 0.14900 0.07860 Si4a -0.89460 -0.14790 -0.08360 O1 0.95810 0.05080 0.07300 O1a -0.94880 -0.04390 -0.06970 O2 0.45390 0.32390 0.07090 O2a -0.45680 -0.32950 -0.06570 O3 0.10690 0.16870 0.25840 O3a -0.11040 -0.16740 -0.26860 O4 0.36970 0.42940 0.22130 O4a -0.37580 -0.44850 -0.25830 O5 0.20420 0.07340 0.09530 O5a -0.20980 -0.07950 -0.09140 O6 0.71290 0.36710 0.03620 O6a -0.71010 -0.36820 -0.04880 O7 0.21420 0.30970 0.07740 O7a -0.20460 -0.30370 -0.06560 O8 0.83420 0.49390 0.02500 O8a -0.83350 -0.49100 -0.02230 O9 0.15930 0.45110 0.22100 O9a -0.16060 -0.44830 -0.22200 O10 0.39640 0.21470 0.25160 O10a -0.39570 -0.20720 -0.25590 O11 0.46330 0.11880 0.02200 O11a -0.46000 -0.12060 -0.02600 O12 0.92560 0.25880 0.02350 O12a -0.92970 -0.25340 -0.03130 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 0.03400 0.04400 0.03400 -0.01600 0.01700 -0.01500 Na2 0.02600 0.04100 0.03200 -0.00800 0.01400 -0.00800 K1 0.02180 0.07200 0.03010 0.00000 0.00860 0.00000 Li1 0.01700 0.02300 0.01900 -0.00900 0.01100 -0.00700 Ti1 0.01060 0.01430 0.01150 -0.00030 0.00390 -0.00030 Fe1 0.01450 0.01920 0.01570 0.00490 0.00650 0.00220 Ti2 0.01210 0.01570 0.10500 -0.00040 0.00460 -0.00070 Fe2 0.01450 0.01800 0.01660 -0.00060 0.00780 -0.00140 Si1 0.00900 0.01500 0.01000 -0.00070 0.00230 -0.00070 Si1a 0.01300 0.01300 0.01200 -0.00010 0.00710 0.00030 Si2 0.01100 0.01400 0.01200 0.00020 0.00530 -0.00030 Si2a 0.01100 0.01100 0.01200 -0.00030 0.00320 -0.00020 Si3 0.01100 0.01500 0.01200 0.00010 0.00440 0.00100 Si3a 0.01200 0.01400 0.01100 0.00050 0.00410 0.00080 Si4 0.01400 0.01300 0.01300 0.00030 0.00600 0.00080 Si4a 0.01200 0.01300 0.01100 0.00010 0.00480 -0.00100 O1 0.01300 0.01500 0.01600 -0.00070 0.00640 -0.00180 O1a 0.01300 0.01500 0.01600 -0.00070 0.00640 -0.00180 O2 0.01200 0.01600 0.01800 0.00210 0.00750 0.00110 O2a 0.01200 0.01600 0.01800 0.00210 0.00750 0.00110 O3 0.02500 0.02100 0.01500 -0.00100 0.01000 -0.00070 O3a 0.02500 0.02100 0.01500 -0.00100 0.01000 -0.00070 O4 0.01800 0.01900 0.01600 -0.00300 0.00700 -0.00400 O4a 0.02100 0.02200 0.01700 0.00000 0.00700 -0.00400 O5 0.01300 0.01700 0.01800 0.00200 0.00710 0.00150 O5a 0.01300 0.01700 0.01800 0.00200 0.00710 0.00150 O6 0.01300 0.01500 0.02200 -0.00700 0.00420 -0.00010 O6a 0.01300 0.01500 0.02200 -0.00070 0.00420 -0.00010 O7 0.01400 0.01400 0.01600 0.00100 0.00600 -0.00020 O7a 0.01400 0.01400 0.01600 0.00100 0.00600 -0.00020 O8 0.02000 0.01800 0.02000 -0.00050 0.01310 0.00330 O8a 0.02000 0.01800 0.02000 -0.00050 0.01310 0.00330 O9 0.01900 0.02400 0.01190 -0.00200 0.00540 -0.00410 O9a 0.01900 0.02400 0.01190 -0.00200 0.00540 -0.00410 O10 0.01700 0.01900 0.01600 -0.00100 0.00290 0.00070 O10a 0.01700 0.01900 0.01600 -0.00100 0.00290 0.00070 O11 0.01400 0.01600 0.02000 -0.00360 0.00510 -0.00240 O11a 0.01400 0.01600 0.02000 -0.00360 0.00510 -0.00240 O12 0.02100 0.01400 0.02100 -0.00100 0.01400 0.00030 O12a 0.02100 0.01400 0.02100 -0.00100 0.01400 0.00030