#------------------------------------------------------------------------------ #$Date: 2012-02-28 14:14:52 +0200 (Tue, 28 Feb 2012) $ #$Revision: 35911 $ #$URL: file:///home/coder/svn-repositories/cod/cif/1/01/02/1010215.cif $ #------------------------------------------------------------------------------ # # This file is available in the Crystallography Open Database (COD), # http://www.crystallography.net/ # # All data on this site have been placed in the public domain by the # contributors. # data_1010215 _chemical_name_systematic 'Dicalcium magnesium disilicate' _chemical_formula_structural 'Ca2 Mg Si2 O7' _chemical_formula_analytical '(Ca, Na)2 (Mg, Al)1 (Si, Al)2 O7' _chemical_formula_sum 'Ca2 Mg O7 Si2' _publ_section_title ; The Structure of Melitite (Ca, Na)~2~ (Mg, Al)~1~ (Si, Al)~2~ O~7~ ; loop_ _publ_author_name 'Warren, B E' _journal_name_full ; Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie (-144,1977) ; _journal_coden_ASTM ZEKGAX _journal_volume 74 _journal_year 1930 _journal_page_first 131 _journal_page_last 138 _cell_length_a 7.73 _cell_length_b 7.73 _cell_length_c 5.01 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 299.4 _cell_formula_units_Z 2 _symmetry_space_group_name_H-M 'P -4 21 m' _symmetry_Int_Tables_number 113 _symmetry_cell_setting tetragonal loop_ _symmetry_equiv_pos_as_xyz 'x,y,z' '1/2-x,1/2+y,-z' '-x,-y,z' '1/2+x,1/2-y,-z' '-y,x,-z' '1/2+y,1/2+x,z' 'y,-x,-z' '1/2-y,1/2-x,z' loop_ _atom_type_symbol _atom_type_oxidation_number Ca2+ 2.000 Si4+ 4.000 Mg2+ 2.000 O2- -2.000 loop_ _atom_site_label _atom_site_type_symbol _atom_site_symmetry_multiplicity _atom_site_Wyckoff_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_attached_hydrogens _atom_site_calc_flag Ca1 Ca2+ 4 e 0.33 0.17 -0.49 1. 0 d Si1 Si4+ 4 e 0.14 0.36 -0.05 1. 0 d Mg1 Mg2+ 2 a 0. 0. 0. 1. 0 d O1 O2- 2 c 0.5 0. 0.19 1. 0 d O2 O2- 4 e 0.14 0.36 0.26 1. 0 d O3 O2- 8 f 0.08 0.18 -0.19 1. 0 d _cod_database_code 1010215