data_global _chemical_name_mineral 'Lopezite' loop_ _publ_author_name 'Weakley T J R' 'Ylvisaker E R' 'Yager R J' 'Stephens J E' 'Wiegel R D' 'Mengis M' 'Wu P' 'Photinos P' 'Abrahams S C' _journal_name_full 'Acta Crystallographica, Section B' _journal_volume 60 _journal_year 2004 _journal_page_first 705 _journal_page_last 715 _publ_section_title ; Phase transitions in K2Cr3O7 and structural redetermination of phase II Sample: Crystal 1 ; _database_code_amcsd 0009931 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Cr2 K2 O7' _cell_length_a 7.3807 _cell_length_b 7.4593 _cell_length_c 13.3910 _cell_angle_alpha 96.205 _cell_angle_beta 98.033 _cell_angle_gamma 90.914 _cell_volume 725.368 _exptl_crystal_density_diffrn 2.694 _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 Cr1 0.59179 0.76891 0.60724 Cr2 0.79289 0.80674 0.41375 Cr3 0.81711 0.42584 0.11354 Cr4 0.81344 0.15250 -0.08323 K1 0.10341 0.66917 0.64038 K2 0.25001 0.76710 0.34950 K3 0.66252 -0.08518 0.15847 K4 0.69509 0.65240 -0.13583 O1 0.72010 0.61240 0.64937 O2 0.55500 0.91020 0.70198 O3 0.40240 0.68490 0.54525 O4 0.70760 0.89370 0.52700 O5 0.95950 0.67490 0.44295 O6 0.86870 0.97090 0.36065 O7 0.63450 0.69520 0.33667 O8 0.68910 0.29270 0.16402 O9 0.97570 0.51810 0.19989 O10 0.69480 0.57510 0.06114 O11 0.92990 0.29570 0.02274 O12 0.69190 -0.00060 -0.04330 O13 0.96000 0.06080 -0.14886 O14 0.67700 0.27380 -0.15168 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 Cr1 0.01900 0.02070 0.01860 0.00273 0.00384 0.00238 Cr2 0.01810 0.02030 0.01880 0.00215 0.00358 0.00476 Cr3 0.01920 0.01830 0.01850 -0.00111 0.00035 0.00206 Cr4 0.01710 0.01820 0.01970 0.00068 0.00301 0.00111 K1 0.03750 0.03150 0.02370 -0.00730 0.00200 0.00550 K2 0.03270 0.02730 0.02900 -0.00250 0.00940 0.00208 K3 0.02360 0.02430 0.02610 -0.00002 0.00360 0.00900 K4 0.03730 0.03020 0.02780 0.01020 0.00350 0.00230 O1 0.03280 0.03190 0.03800 0.00930 -0.00010 0.01000 O2 0.04340 0.03360 0.02940 0.00310 0.01620 -0.00290 O3 0.02640 0.04610 0.03380 -0.00430 -0.00200 0.00440 O4 0.03810 0.02480 0.02940 0.00100 0.01680 0.00270 O5 0.02720 0.03280 0.02740 0.01070 0.00320 0.00680 O6 0.04230 0.02800 0.03240 -0.00140 0.01090 0.01170 O7 0.02730 0.04380 0.03440 -0.00530 -0.00180 -0.00030 O8 0.03020 0.02900 0.03360 -0.00700 0.00840 0.00450 O9 0.03010 0.03660 0.02200 -0.01050 0.00000 -0.00100 O10 0.04070 0.03170 0.03100 0.01400 0.00240 0.00530 O11 0.01950 0.02690 0.02540 0.00000 0.00040 -0.00260 O12 0.03680 0.02450 0.02780 -0.00780 0.00550 0.00460 O13 0.02900 0.04310 0.03960 0.00670 0.01230 -0.00680 O14 0.02690 0.02490 0.02860 0.00220 -0.00160 0.00650