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#$Date: 2012-02-28 17:44:07 +0200 (Tue, 28 Feb 2012) $
#$Revision: 35913 $
#$URL: file:///home/coder/svn-repositories/cod/cif/9/01/36/9013638.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_9013638
loop_
_publ_author_name
'Merlini, M.'
'Gemmi, M.'
'Hanfland, M.'
'Crichton, W.'
_publ_section_title
;
 High-pressure behavior of akermanite and gehlenite and phase stability
 of the normal structures in melelites
 Note: P = 15.7 GPa
 Locality: synthetic
;
_journal_name_full               'American Mineralogist'
_journal_page_first              704
_journal_page_last               709
_journal_volume                  94
_journal_year                    2009
_chemical_formula_sum            'Ca2 Mg O7 Si2'
_chemical_name_mineral           Akermanite
_space_group_IT_number           14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_cell_angle_alpha                90
_cell_angle_beta                 115.1
_cell_angle_gamma                90
_cell_length_a                   8.82
_cell_length_b                   7.34
_cell_length_c                   9.13
_cell_volume                     535.250
_diffrn_ambient_pressure         1.57e+07
_exptl_crystal_density_diffrn    3.383
_[local]_cod_chemical_formula_sum_orig 'Mg Si2 Ca2 O7'
_cod_database_code               9013638
_amcsd_database_code             AMCSD#0004934
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
1/2+x,1/2-y,1/2+z
1/2-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
Mg 0.81070 0.09970 0.09260
Si1 0.86480 0.45120 0.21500
Si2 0.95750 0.75540 0.07310
Ca1 0.45930 0.27940 0.02940
Ca2 0.30280 0.56380 0.21210
O1 0.99750 0.56180 0.15930
O2 0.88010 0.52210 0.37910
O3 0.69800 0.47280 0.04100
O4 0.00490 0.88000 0.22570
O5 0.12630 0.82080 0.06620
O6 0.95300 0.26250 0.28560
O7 0.78300 0.75830 -0.09700