data_global _amcsd_formula_title 'Ca0.77 Cu2 Hg0.3 Nd0.23 O7 Pb0.7 Sr2' loop_ _publ_author_name 'Martin C' 'Hervieu M' 'Huve M' 'Michel C' 'Maignan A' 'Van Tendeloo G' 'Raveau B' _journal_name_full 'Physica C' _journal_volume 222 _journal_year 1994 _journal_page_first 19 _journal_page_last 26 _publ_section_title ; Lead-mercury-based superconductors. The 1212 cuprate Pb0.7Hg0.3Sr2+x Ca0.7Nd0.3-xCu2O7-d and the new oxycarbonate Pb0.7Hg0.3Sr4Cu2(CO3)O7 _cod_database_code 1001631 ; _database_code_amcsd 0015062 _chemical_formula_sum 'Pb.7 Hg.3 Sr2 (Nd.23 Ca.77) Cu2 O7' _cell_length_a 3.8116 _cell_length_b 3.8116 _cell_length_c 12.1337 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 176.282 _exptl_crystal_density_diffrn 6.439 _symmetry_space_group_name_H-M 'P 4/m m m' loop_ _space_group_symop_operation_xyz 'x,y,z' '-y,-x,z' 'y,x,-z' 'y,-x,-z' '-y,x,z' 'x,-y,z' '-x,y,-z' 'x,y,-z' '-x,-y,z' 'y,x,z' '-y,-x,-z' '-y,x,-z' 'y,-x,z' '-x,y,z' 'x,-y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Pb1 0.06500 0.00000 0.00000 0.17500 Hg1 0.06500 0.00000 0.00000 0.07500 Sr1 0.50000 0.50000 0.21450 1.00000 Nd1 0.50000 0.50000 0.50000 0.23000 Ca1 0.50000 0.50000 0.50000 0.77000 Cu1 0.00000 0.00000 0.36090 1.00000 O1 0.50000 0.50000 0.00000 1.00000 O2 0.00000 0.00000 0.16800 1.00000 O3 0.00000 0.50000 0.37100 1.00000