data_global _amcsd_formula_title 'B2 Gd2 Na2 O7' loop_ _publ_author_name 'Corbel G' 'Leblanc M' 'Antic-Fidancev E' 'Lemaitre-Blaise M' _journal_name_full 'Journal of Solid State Chemistry' _journal_volume 144 _journal_year 1999 _journal_page_first 35 _journal_page_last 44 _publ_section_title ; Crystal structure of sodium rare earth oxyborates Na2Ln2(BO3)2O (Ln = Sm,Eu, and Gd) and optical analysis of Na2Gd2(BO3)2O:Eu(3+) _cod_database_code 1000502 ; _database_code_amcsd 0013972 _chemical_formula_sum 'Gd2 Na2 O7 B2' _cell_length_a 10.695 _cell_length_b 6.320 _cell_length_c 10.328 _cell_angle_alpha 90 _cell_angle_beta 117.80 _cell_angle_gamma 90 _cell_volume 617.521 _exptl_crystal_density_diffrn 5.315 _symmetry_space_group_name_H-M 'P 1 21/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,1/2+z' '-x,1/2+y,1/2-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Gd1 0.18531 0.08225 0.08949 Gd2 0.98249 0.45948 0.18103 Na1 0.52290 -0.05730 0.26240 Na2 0.60940 0.26220 0.04690 O1 0.97280 0.12350 0.09590 O2 0.31790 -0.25560 0.13590 O3 0.17000 0.26210 0.36450 O4 0.15040 0.45940 0.08770 O5 0.39800 0.16200 0.05520 O6 0.84860 0.25810 0.27160 O7 0.37270 0.14900 0.34010 B1 0.31830 0.25100 0.07970 B2 0.20970 -0.34700 0.14960 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 Gd1 0.00620 0.00380 0.00610 -0.00010 0.00270 0.00000 Gd2 0.00670 0.00330 0.00550 0.00030 0.00320 0.00000 Na1 0.01300 0.01400 0.01700 0.00000 0.00500 0.00100 Na2 0.01700 0.02900 0.01800 -0.00200 0.01000 0.00500 O1 0.00900 0.00600 0.00700 0.00100 0.00400 -0.00100 O2 0.01100 0.00900 0.01600 0.00000 0.00900 0.00000 O3 0.00800 0.01000 0.00700 0.00000 0.00300 0.00200 O4 0.01200 0.00500 0.01200 0.00100 0.00700 0.00100 O5 0.00900 0.01500 0.00700 0.00100 0.00200 0.00400 O6 0.01100 0.00800 0.00900 0.00100 0.00500 0.00100 O7 0.01300 0.01600 0.01200 0.00100 0.00700 -0.00400