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#$Date: 2024-04-25 17:59:02 +0300 (Thu, 25 Apr 2024) $
#$Revision: 291351 $
#$URL: file:///home/coder/svn-repositories/cod/cif/9/00/29/9002917.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_9002917
loop_
_publ_author_name
'Thompson, R. M.'
'Downs, R. T.'
_publ_section_title
;Model pyroxenes I: Ideal pyroxene topologies Pyroxene #9a based on stacking
 sequence ABABCBAC 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
_space_group_IT_number           13
_symmetry_space_group_name_Hall  '-P 2yc'
_symmetry_space_group_name_H-M   'P 1 2/c 1'
_cell_angle_alpha                90
_cell_angle_beta                 90.
_cell_angle_gamma                90
_cell_length_a                   13.0639452948
_cell_length_b                   6
_cell_length_c                   3.46410161514
_cell_formula_units_Z            16
_cell_volume                     271.529
_exptl_crystal_density_diffrn    9.823
_cod_original_formula_sum        'Si Mg O3'
_cod_database_code               9002917
_cod_struct_determination_method theoretical
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
x,-y,1/2+z
-x,y,1/2-z
-x,-y,-z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
SiA 0.90625 0.91667 0.08333
SiB 0.84375 0.41667 0.91667
SiC 0.40625 0.91667 0.75000
SiD 0.34375 0.58333 0.41667
Mg1a 0.00000 0.41667 0.25000
Mg2a 0.00000 0.25000 0.75000
Mg1b 0.25000 0.91667 0.08333
Mg2b 0.25000 0.25000 0.08333
Mg1c 0.50000 0.58333 0.75000
Mg2c 0.50000 0.25000 0.75000
O1A 0.81250 0.91667 0.08333
O2A 0.93750 0.75000 0.91667
O3A 0.93750 0.08333 0.91667
O1B 0.93750 0.41667 0.91667
O2B 0.81250 0.25000 0.08333
O3B 0.81250 0.58333 0.08333
O1C 0.31250 0.91667 0.75000
O2C 0.43750 0.75000 0.91667
O3C 0.43750 0.08333 0.91667
O1D 0.43750 0.58333 0.41667
O2D 0.31250 0.75000 0.25000
O3D 0.31250 0.58333 0.75000
_database_code_amcsd 0003006
