data_global _chemical_name_mineral 'Leucophanite' loop_ _publ_author_name 'Grice J D' 'Hawthorne F C' _journal_name_full 'The Canadian Mineralogist' _journal_volume 27 _journal_year 1989 _journal_page_first 193 _journal_page_last 197 _publ_section_title ; Refinement of the crystal structure of leucophanite ; _database_code_amcsd 0005227 _chemical_formula_sum 'Na Ca Be Si2 O6 F' _cell_length_a 7.401 _cell_length_b 7.412 _cell_length_c 9.990 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 548.014 _exptl_crystal_density_diffrn 2.948 _symmetry_space_group_name_H-M 'P 21 21 21' loop_ _space_group_symop_operation_xyz 'x,y,z' '-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 Na 0.10210 0.67820 0.24650 Ca 0.07880 0.64620 0.75990 Be 0.12000 0.35920 0.53070 Si1 0.10000 0.35800 0.02410 Si2 0.23710 0.99170 0.99940 O1 0.09120 0.35480 0.86450 O2 0.14830 0.15800 0.08950 O3 0.09860 0.91360 0.41110 O4 0.08000 0.91290 0.90300 O5 0.17690 0.16260 0.59350 O6 0.25530 0.50760 0.58920 F 0.12160 0.35260 0.37290 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 Na 0.01800 0.02500 0.01710 0.00520 0.00450 -0.00640 Ca 0.01160 0.00890 0.00910 0.00210 0.00060 0.00250 Be 0.00300 0.00040 0.00490 0.00000 0.00000 0.00000 Si1 0.00660 0.00730 0.00910 0.00000 0.00000 -0.00020 Si2 0.00680 0.00690 0.00980 0.00030 -0.00110 -0.00050 O1 0.01290 0.00960 0.00900 0.00110 0.00170 0.00030 O2 0.01240 0.00670 0.01100 0.00090 0.00130 0.00010 O3 0.00770 0.01160 0.01090 -0.00090 0.00080 0.00000 O4 0.00650 0.01140 0.01160 -0.00080 -0.00150 -0.00290 O5 0.01150 0.00660 0.01100 0.00100 0.00310 -0.00140 O6 0.00990 0.01040 0.01010 -0.00060 0.00280 0.00200 F 0.01620 0.01910 0.01230 -0.00030 0.00010 -0.00180