data_global _chemical_name_mineral 'Cervandonite-(Ce)' loop_ _publ_author_name 'Demartin F' 'Gramaccioli C M' 'Graeser S' _journal_name_full 'The Canadian Mineralogist' _journal_volume 46 _journal_year 2008 _journal_page_first 423 _journal_page_last 430 _publ_section_title ; The crystal structure of cervandonite-(Ce), an interesting example of As3+ - Si diadochy Note: Chemistry from original description of the mineral. ; _database_code_amcsd 0006185 _chemical_compound_source 'Alpine fissures at Pizzo Cervandone, Scherbadung, Central Alps' _chemical_formula_sum '(Ce.44 Nd.22 La.21 Th.06 Y.03 U.02 Ca.02) Fe1.671 Ti.939 Al.381 Sn.009 As1.16 Si1.68 O13' _cell_length_a 6.508 _cell_length_b 6.508 _cell_length_c 18.520 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 679.308 _exptl_crystal_density_diffrn 4.667 _symmetry_space_group_name_H-M 'R 3 m' loop_ _space_group_symop_operation_xyz 'x,y,z' '2/3+x,1/3+y,1/3+z' '1/3+x,2/3+y,2/3+z' 'x,x-y,z' '2/3+x,1/3+x-y,1/3+z' '1/3+x,2/3+x-y,2/3+z' '-y,-x,z' '2/3-y,1/3-x,1/3+z' '1/3-y,2/3-x,2/3+z' '-x+y,y,z' '2/3-x+y,1/3+y,1/3+z' '1/3-x+y,2/3+y,2/3+z' '-y,x-y,z' '2/3-y,1/3+x-y,1/3+z' '1/3-y,2/3+x-y,2/3+z' '-x+y,-x,z' '2/3-x+y,1/3-x,1/3+z' '1/3-x+y,2/3-x,2/3+z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv Ce 0.00000 0.00000 0.00000 0.44000 0.02030 Nd 0.00000 0.00000 0.00000 0.22000 0.02030 La 0.00000 0.00000 0.00000 0.21000 0.02030 Th 0.00000 0.00000 0.00000 0.06000 0.02030 Y 0.00000 0.00000 0.00000 0.03000 0.02030 U 0.00000 0.00000 0.00000 0.02000 0.02030 Ca 0.00000 0.00000 0.00000 0.02000 0.02030 Fe3+ 0.16820 0.33650 -0.16610 0.41700 0.03090 Fe2+ 0.16820 0.33650 -0.16610 0.14000 0.03090 Ti 0.16820 0.33650 -0.16610 0.31300 0.03090 Al 0.16820 0.33650 -0.16610 0.12700 0.03090 Sn 0.16820 0.33650 -0.16610 0.00300 0.03090 As1 0.33333 0.66667 0.34700 0.58000 0.01830 As2 0.33333 0.66667 -0.01560 0.58000 0.03110 Si1 0.33333 0.66667 0.36980 0.42000 0.02910 Si2 0.33333 0.66667 0.19280 0.42000 0.01880 Si3 0.33333 0.66667 0.14240 0.42000 0.01880 Si4 0.33333 0.66667 -0.03550 0.42000 0.02910 O1 0.00000 0.00000 -0.14040 1.00000 0.07100 O2 0.00000 0.00000 0.14000 1.00000 0.07200 O3 0.20240 0.40480 0.16730 1.00000 0.02910 O4 0.06080 0.53040 0.39260 1.00000 0.03490 O5 0.19260 0.38530 -0.06380 1.00000 0.02370 O6 0.33333 0.66667 0.28240 1.00000 0.03800 O7 0.33333 0.66667 0.05320 1.00000 0.02300 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 Ce 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 Nd 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 La 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 Th 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 Y 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 U 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 Ca 0.02250 0.02250 0.01590 0.01130 0.00000 0.00000 Fe3+ 0.02860 0.05850 0.01570 0.02920 0.00200 0.00400 Fe2+ 0.02860 0.05850 0.01570 0.02920 0.00200 0.00400 Ti 0.02860 0.05850 0.01570 0.02920 0.00200 0.00400 Al 0.02860 0.05850 0.01570 0.02920 0.00200 0.00400 Sn 0.02860 0.05850 0.01570 0.02920 0.00200 0.00400 As1 0.02320 0.02320 0.00840 0.01160 0.00000 0.00000 As2 0.04000 0.04000 0.01330 0.02000 0.00000 0.00000