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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/9/00/29/9002923.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_9002923
loop_
_publ_author_name
'Thompson, R. M.'
'Downs, R. T.'
_publ_section_title
;Model pyroxenes I: Ideal pyroxene topologies Pyroxene #12b based on stacking
 sequence ABABABABCBAC 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           14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_cell_angle_alpha                90
_cell_angle_beta                 90.
_cell_angle_gamma                90
_cell_length_a                   19.5959179423
_cell_length_b                   6
_cell_length_c                   3.46410161514
_cell_formula_units_Z            24
_cell_volume                     407.294
_exptl_crystal_density_diffrn    9.823
_cod_original_formula_sum        'Mg Si O3'
_cod_database_code               9002923
_cod_struct_determination_method theoretical
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
x,1/2-y,1/2+z
-x,1/2+y,1/2-z
-x,-y,-z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Mg1a 0.08333 0.66667 0.50000
Mg2a 0.08333 0.50000 0.00000
Mg1b 0.25000 0.33333 0.50000
Mg2b 0.25000 0.50000 0.00000
Mg1c 0.41667 0.66667 0.83333
Mg2c 0.41667 0.50000 0.33333
SiA 0.14583 0.16667 0.33333
SiB 0.18750 0.83333 0.66667
SiC 0.31250 0.66667 0.50000
SiD 0.35417 0.33333 0.16667
SiE 0.47917 0.16667 0.33333
SiF 0.02083 0.16667 0.66667
O1A 0.20833 0.16667 0.33333
O2A 0.12500 0.00000 0.16667
O3A 0.12500 0.16667 0.66667
O1B 0.12500 0.83333 0.66667
O2B 0.20833 0.00000 0.83333
O3B 0.20833 0.83333 0.33333
O1C 0.37500 0.66667 0.50000
O2C 0.29167 0.50000 0.66667
O3C 0.29167 0.83333 0.66667
O1D 0.29167 0.33333 0.16667
O2D 0.37500 0.50000 0.00000
O3D 0.37500 0.16667 0.00000
O1E 0.54167 0.16667 0.33333
O2E 0.45833 0.00000 0.16667
O3E 0.45833 0.16667 0.66667
O1F 0.95833 0.16667 0.66667
O2F 0.04167 0.00000 0.83333
O3F 0.04167 0.16667 0.33333
_database_code_amcsd 0003012
