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 = 293 K ; _database_code_amcsd 0007532 _chemical_compound_source 'San Benito, California, USA' _chemical_formula_sum 'Na2 K Li Ti2 Fe2 Si8 O24' _cell_length_a 16.427 _cell_length_b 12.478 _cell_length_c 9.975 _cell_angle_alpha 90 _cell_angle_beta 115.56 _cell_angle_gamma 90 _cell_volume 1844.536 _exptl_crystal_density_diffrn 3.270 _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 0.26690 0.19650 0.31400 Na2 -0.26130 -0.19920 -0.30090 K1 0.00000 0.42058 0.25000 Li1 0.50200 0.43530 0.25600 Ti1 0.34250 0.32500 0.10340 Fe1 -0.33760 -0.31636 -0.09610 Ti2 0.08820 0.05243 0.11440 Fe2 -0.08770 -0.06111 -0.11180 Si1 0.14690 0.40781 0.06160 Sia -0.14360 -0.40499 -0.05880 Si2 0.52480 0.22580 0.08530 Si2a -0.52140 -0.22887 -0.08520 Si3 0.77060 0.47290 0.10960 Si3a -0.76980 -0.47541 -0.10870 Si4 0.89540 0.15005 0.07970 Si4a -0.89420 -0.14857 -0.08360 O1 0.95750 0.05060 0.07170 O1a -0.94940 -0.04450 -0.07170 O2 0.45530 0.32410 0.07190 O2a -0.45630 -0.32960 -0.06680 O3 0.10840 0.16770 0.25830 O3a -0.10990 -0.16950 -0.26710 O4 0.37080 0.43030 0.22400 O4a -0.37530 -0.44930 -0.25800 O5 0.20580 0.07400 0.09610 O5a -0.20900 -0.07920 -0.09010 O6 0.71330 0.36420 0.03860 O6a -0.70920 -0.36760 -0.04940 O7 0.21380 0.30980 0.07770 O7a -0.20500 -0.30310 -0.06590 O8 0.83280 0.49330 0.02230 O8a -0.83250 -0.48930 -0.01980 O9 0.15860 0.45140 0.22260 O9a -0.15950 -0.44770 -0.22170 O10 0.39690 0.21280 0.25070 O10a -0.39400 -0.20900 -0.25670 O11 0.46430 0.11610 0.02580 O11a -0.45970 -0.12000 -0.02750 O12 0.92720 0.26000 0.02480 O12a -0.93050 -0.25540 -0.03380 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 0.01600 0.02320 0.01900 -0.00740 0.01010 -0.00700 Na2 0.01400 0.02140 0.01560 -0.00430 0.00710 -0.00510 K1 0.01110 0.03660 0.01710 0.00050 0.00510 0.00100 Li1 0.01200 0.01700 0.01300 -0.00900 0.00900 -0.00800 Ti1 0.00570 0.00630 0.00590 0.00030 0.00260 -0.00010 Fe1 0.00700 0.01000 0.00810 0.00310 0.00340 0.00120 Ti2 0.00640 0.00770 0.00560 -0.00080 0.00340 -0.00050 Fe2 0.00720 0.00950 0.00830 -0.00010 0.00380 -0.00120 Si1 0.00470 0.00630 0.00480 -0.00070 0.00180 -0.00060 Sia 0.00590 0.00590 0.00580 0.00030 0.00320 0.00050 Si2 0.00550 0.00630 0.00710 -0.00040 0.00360 -0.00060 Si2a 0.00470 0.00540 0.00480 -0.00040 0.00160 -0.00040 Si3 0.00610 0.00670 0.00540 0.00020 0.00310 0.00090 Si3a 0.00510 0.00640 0.00550 0.00000 0.00210 0.00020 Si4 0.00530 0.00660 0.00560 -0.00010 0.00290 0.00060 Si4a 0.00700 0.00490 0.00570 0.00080 0.00350 0.00000 O1 0.00750 0.00740 0.00920 0.00000 0.00430 -0.00060 O1a 0.00750 0.00740 0.00920 0.00000 0.00420 -0.00060 O2 0.00720 0.00700 0.00900 0.00140 0.00430 0.00070 O2a 0.00720 0.00700 0.00900 0.00140 0.00430 0.00070 O3 0.01300 0.01050 0.00780 -0.00220 0.00640 -0.00080 O3a 0.01300 0.01050 0.00780 -0.00080 0.00640 -0.00080 O4 0.01000 0.01000 0.00900 -0.00120 0.00470 -0.00290 O4a 0.01300 0.01000 0.01100 0.00090 0.00700 -0.00210 O5 0.00790 0.00840 0.00900 0.00180 0.00450 0.00090 O5a 0.00790 0.00840 0.00900 0.00180 0.00450 0.00090 O6 0.00750 0.00830 0.01090 -0.00010 0.00280 -0.00020 O6a 0.00750 0.00830 0.01080 -0.00010 0.00280 -0.00020 O7 0.00770 0.00740 0.00890 0.00120 0.00420 -0.00060 O7a 0.00770 0.00740 0.00890 0.00120 0.00420 -0.00060 O8 0.01000 0.00880 0.01090 0.00100 0.00730 0.00230 O8a 0.01000 0.00880 0.01090 0.00100 0.00730 0.00230 O9 0.00990 0.01290 0.00570 0.00010 0.00290 -0.00220 O9a 0.00990 0.01290 0.00570 0.00010 0.00290 -0.00220 O10 0.00820 0.00990 0.00790 -0.00050 0.00130 0.00130 O10a 0.00820 0.00990 0.00790 -0.00050 0.00130 0.00130 O11 0.00600 0.00830 0.01100 -0.00080 0.00240 -0.00130 O11a 0.00600 0.00830 0.01100 -0.00080 0.00240 -0.00130 O12 0.01160 0.00670 0.01070 -0.00040 0.00750 0.00100 O12a 0.01160 0.00670 0.01070 -0.00040 0.00750 0.00100