#------------------------------------------------------------------------------ #$Date: 2023-11-15 17:55:45 +0200 (Wed, 15 Nov 2023) $ #$Revision: 287617 $ #$URL: file:///home/coder/svn-repositories/cod/cif/9/00/29/9002908.cif $ #------------------------------------------------------------------------------ # # This file is available in the Crystallography Open Database (COD), # http://www.crystallography.net/. The original data for this entry # were provided the American Mineralogist Crystal Structure Database, # http://rruff.geo.arizona.edu/AMS/amcsd.php # # The file may be used within the scientific community so long as # proper attribution is given to the journal article from which the # data were obtained. # data_9002908 loop_ _publ_author_name 'Thompson, R. M.' 'Downs, R. T.' _publ_section_title ;Model pyroxenes I: Ideal pyroxene topologies Pyroxene #2 based on stacking sequence ABAC. Ideal analogue of protopyroxene, high-P protopyroxene. Note: Atoms Mg, Si, and O are assigned to atomic positions just for convenience. ; _journal_name_full 'American Mineralogist' _journal_page_first 653 _journal_page_last 666 _journal_paper_doi 10.2138/am-2003-0419 _journal_volume 88 _journal_year 2003 _chemical_formula_structural Mg2(Si2O6) _chemical_formula_sum 'Mg O3 Si' _chemical_name_mineral Pyroxene-ideal _symmetry_space_group_name_H-M 'P 21 c n' _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_length_a 6.53197264742 _cell_length_b 6 _cell_length_c 3.46410161514 _cell_volume 135.765 _exptl_crystal_density_diffrn 9.823 _cod_original_cell_volume 135.764 _cod_original_formula_sum 'Mg Si O3' _cod_database_code 9002908 _cod_struct_determination_method theoretical loop_ _symmetry_equiv_pos_as_xyz x,y,z x,-y,1/2+z 1/2+x,1/2+y,1/2-z 1/2+x,1/2-y,-z loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Mg1 0.00000 0.08333 0.66667 Mg2 0.00000 0.25000 0.16667 SiA 0.68750 0.91667 0.83333 SiB 0.31250 0.08333 0.00000 O1A 0.87500 0.91667 0.83333 O1B 0.12500 0.08333 0.00000 O2A 0.62500 0.75000 0.00000 O2B 0.37500 0.25000 0.16667 O3A 0.62500 0.91667 0.50000 O3B 0.37500 0.91667 0.16667 _database_code_amcsd 0002997