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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/9/00/19/9001997.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_9001997
loop_
_publ_author_name
'Oberti, R.'
'Hawthorne, F. C.'
'Camara, F.'
'Raudsepp, M.'
_publ_section_title
;
 Unusual M3+ cations in synthetic amphiboles with nominal fluoro-eckermannite
 composition: Deviations from stoichiometry and structural effects of the
 cummingtonite component
 Sample: Cr1, Na1.00Na1.97Mg.03Mg4.03Cr.97Si8O22F2
;
_journal_name_full               'American Mineralogist'
_journal_page_first              102
_journal_page_last               111
_journal_volume                  84
_journal_year                    1999
_chemical_formula_sum            'Cr0.98 F2 Mg4.12 Na2.91 O22 Si8'
_chemical_name_mineral           Fluoro-eckermannite
_space_group_IT_number           12
_symmetry_space_group_name_Hall  '-C 2y'
_symmetry_space_group_name_H-M   'C 1 2/m 1'
_cell_angle_alpha                90
_cell_angle_beta                 103.69
_cell_angle_gamma                90
_cell_length_a                   9.722
_cell_length_b                   17.813
_cell_length_c                   5.282
_cell_volume                     888.739
_exptl_crystal_density_diffrn    3.112
_[local]_cod_chemical_formula_sum_orig 'Si8 Mg4.12 Cr.98 Na2.91 O22 F2'
_cod_database_code               9001997
_amcsd_database_code             AMCSD#0002058
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
-x,y,-z
1/2-x,1/2+y,-z
-x,-y,-z
1/2-x,1/2-y,-z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
Si(1) 0.28340 0.08590 0.29390 1.00000 0.00545
Si(2) 0.28980 0.17190 0.80180 1.00000 0.00583
Mg(1) 0.00000 0.08950 0.50000 1.00000 0.00671
Cr(2) 0.00000 0.17820 0.00000 0.49000 0.00570
Mg(2) 0.00000 0.17820 0.00000 0.51000 0.00570
Mg(3) 0.00000 0.00000 0.00000 1.00000 0.00697
Mg(4) 0.00000 0.27430 0.50000 0.05000 0.01558
Na(4) 0.00000 0.27430 0.50000 0.95000 0.01558
NaA 0.00000 0.50000 0.00000 0.27000 0.02419
NaA(m) 0.04420 0.50000 0.09300 0.27000 0.02698
NaA(2) 0.00000 0.47250 0.00000 0.10000 0.03470
O1 0.11300 0.08700 0.21340 1.00000 0.00785
O2 0.11880 0.16780 0.73350 1.00000 0.00735
F3 0.10410 0.00000 0.70680 1.00000 0.01013
O4 0.36200 0.25120 0.79770 1.00000 0.01039
O5 0.35270 0.12910 0.08380 1.00000 0.00937
O6 0.34450 0.11910 0.58440 1.00000 0.00925
O7 0.34210 0.00000 0.29350 1.00000 0.00988