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#$Date: 2010-06-10 18:11:07 +0300 (Thu, 10 Jun 2010) $
#$Revision: 1210 $
#$URL: file:///home/coder/svn-repositories/cod/cif/9/9001998.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_9001998
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: Cr2, Na1.00Na1.75Mg.25Mg4.25Cr.75Si8O22F2
;
_journal_name_full               'American Mineralogist'
_journal_page_first              102
_journal_page_last               111
_journal_volume                  84
_journal_year                    1999
_chemical_formula_sum            'Cr0.76 F2 Mg4.42 Na2.51 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                 103.66
_cell_angle_gamma                90
_cell_length_a                   9.728
_cell_length_b                   17.825
_cell_length_c                   5.278
_cell_volume                     889.326
_exptl_crystal_density_diffrn    3.060
_[local]_cod_chemical_formula_sum_orig 'Si8 Mg4.42 Cr.76 Na2.51 O22 F2'
_cod_database_code               9001998
_amcsd_database_code             AMCSD#0002059
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) 0.28350 0.08570 0.29240 1.00000 0.00469
Si(2) 0.28970 0.17180 0.79990 1.00000 0.00469
Mg(1) 0.00000 0.08980 0.50000 1.00000 0.00646
Cr(2) 0.00000 0.17850 0.00000 0.38000 0.00431
Mg(2) 0.00000 0.17850 0.00000 0.62000 0.00431
Mg(3) 0.00000 0.00000 0.00000 1.00000 0.00481
Mg(4) 0.00000 0.27400 0.50000 0.05000 0.01710
Na(4) 0.00000 0.27400 0.50000 0.95000 0.01710
NaA 0.00000 0.50000 0.00000 0.27000 0.02520
NaA(m) 0.04020 0.50000 0.09460 0.09000 0.03014
NaA(2) 0.00000 0.47430 0.00000 0.08000 0.02812
Mg(4*) 0.00000 0.24410 0.50000 0.04000 0.00519
O1 0.11280 0.08590 0.21360 1.00000 0.00659
O2 0.11890 0.16780 0.73160 1.00000 0.00633
F3 0.10290 0.00000 0.70910 1.00000 0.00785
O4 0.36180 0.25100 0.79470 1.00000 0.01077
O5 0.35220 0.12940 0.08280 1.00000 0.00874
O6 0.34450 0.11880 0.58260 1.00000 0.00950
O7 0.34300 0.00000 0.29090 1.00000 0.00899