data_global _amcsd_formula_title 'O7 Si2 Sm2' loop_ _publ_author_name 'Norlund Christensen A' 'Frost Jensen A' 'Kruse Themsen B' 'Gronbaek Hazell R' 'Hanfland M' 'Dooryhee E' _journal_name_full 'Acta Chemica Scandinavica' _journal_volume 51 _journal_year 1997 _journal_page_first 1178 _journal_page_last 1185 _publ_section_title ; Structure investigations of the high-temperature phases of La2 Si2 O7, Gd2 Si2 O7 and Sm2 Si2 O7 _cod_database_code 1008805 ; _database_code_amcsd 0016676 _chemical_formula_sum 'Sm2 Si2 O7' _cell_length_a 8.553 _cell_length_b 12.849 _cell_length_c 5.392 _cell_angle_alpha 91.08 _cell_angle_beta 88.61 _cell_angle_gamma 89.68 _cell_volume 592.277 _exptl_crystal_density_diffrn 5.258 _symmetry_space_group_name_H-M 'P -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Sm1 0.18540 0.76780 0.24180 Sm2 0.40090 0.59160 0.75650 Sm3 0.29870 0.26620 0.75680 Sm4 0.10290 0.08860 0.25880 Si1 -0.00290 0.32010 0.28040 Si2 0.24890 0.97620 0.71350 Si3 0.24590 0.47940 0.21580 Si4 0.50380 0.82180 0.78070 O1 0.35170 0.42000 -0.00250 O2 0.14440 0.92030 0.49330 O3 0.08120 0.25850 0.50780 O4 0.81750 0.32350 0.37330 O5 0.02370 0.24780 0.03170 O6 0.41350 0.76270 0.00460 O7 0.24280 0.09610 0.63990 O8 0.67780 0.83450 0.87940 O9 0.24280 0.59580 0.12820 O10 0.06910 0.43690 0.23500 O11 0.34350 0.46210 0.46250 O12 0.49920 0.74480 0.53720 O13 0.15240 0.94950 0.96930 O14 0.42750 0.93540 0.71870 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 Sm1 0.00950 0.00570 0.00610 0.00050 0.00200 0.00010 Sm2 0.00740 0.00580 0.00450 0.00060 -0.00020 0.00070 Sm3 0.00890 0.00700 0.00660 -0.00050 -0.00130 -0.00170 Sm4 0.00720 0.00560 0.00480 -0.00070 0.00000 0.00060 Si1 0.01250 0.00400 0.00480 -0.00180 -0.00260 0.00160 Si2 0.00750 0.00500 0.00470 0.00240 0.00070 0.00040 Si3 0.01390 0.00180 0.00520 0.00030 -0.00170 -0.00030 Si4 0.00780 0.00840 0.00560 -0.00090 0.00110 0.00320 O1 0.00760 0.01690 0.00800 -0.00470 -0.00580 -0.00210 O2 0.01330 0.00930 0.00700 0.00030 0.00010 -0.00040 O3 0.00590 0.01310 0.00000 0.00090 -0.01050 -0.00340 O4 0.00500 0.01860 0.00390 0.00830 -0.00510 0.01230 O5 0.00930 0.01110 0.01330 0.00010 0.00670 0.00350 O6 0.01300 0.00530 0.02250 -0.00520 0.01270 0.00580 O7 0.01600 0.00060 0.02370 -0.00180 -0.01140 -0.00060 O8 0.01100 0.00980 0.01090 -0.00260 0.00480 0.00580 O9 0.00260 0.00930 0.01400 0.00160 0.00240 -0.00640 O10 0.01170 0.02400 0.02680 0.00340 -0.00030 0.01510 O11 0.02140 0.01840 0.00360 0.00160 0.00140 0.00170 O12 0.01510 0.01240 0.01790 -0.00250 0.00200 -0.00240 O13 0.01590 0.02050 0.00620 -0.01030 0.00270 -0.00320 O14 0.00760 0.01190 0.02630 -0.00490 0.00250 0.01200