#------------------------------------------------------------------------------
#$Date: 2008-01-14 00:15:36 +0200 (Mon, 14 Jan 2008) $
#$Revision: 14 $
#$URL: file:///home/coder/svn-repositories/cod/cif/1/1100024.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_1100024
_chemical_name_systematic          'Calcium strontium silicate (1.8/.2/1)'
_chemical_formula_structural       'Ca1.8 Sr.2 Si O4'
_chemical_formula_sum              'Ca1.8 O4 Si Sr.2'
_publ_section_title
;
Order-Disorder in the $-alpha-(Ca, Sr)~2~ Si O~4~ Solid Solution: a
Structural and Statistical-Thermodynamic Analysis
;
loop_
_publ_author_name
  'Catti, M'
  'Gazzoni, G'
  'Ivaldi, G'
_journal_name_full                 'Acta Crystallographica B (39,1983-)'
_journal_volume                    40
_journal_year                      1984
_journal_page_first                537
_journal_page_last                 544
_cell_length_a                     5.647(1)
_cell_length_b                     7.037(1)
_cell_length_c                     9.644(2)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       383.2
_cell_formula_units_Z              4
_symmetry_space_group_name_H-M     'P m n b'
_symmetry_Int_Tables_number        62
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2-x,1/2+y,1/2-z'
  '1/2+x,-y,-z'
  '-x,1/2-y,1/2+z'
  '-x,-y,-z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,y,z'
  'x,1/2+y,1/2-z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Ca2+   2.000
  Sr2+   2.000
  Si4+   4.000
  O2-   -2.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Ca1   Ca2+   8 d 0.2717(6) 0.33564(8) 0.57308(6) 0.410(5)  0 d
  Sr1   Sr2+   8 d 0.2717(6) 0.33564(8) 0.57308(6) 0.09  0 d
  Ca2   Ca2+   8 d 0.2716(7) -0.00754(8) 0.29688(6) 0.49  0 d
  Sr2   Sr2+   8 d 0.2716(7) -0.00754(8) 0.29688(6) 0.01  0 d
  Si1   Si4+   4 c 0.25 0.7811(1) 0.58534(8) 1.  0 d
  O1    O2-    8 d 0.3087(5) 1.0077(4) 0.5502(3) 0.5  0 d
  O2    O2-    8 d 0.1811(6) 0.6598(4) 0.4375(3) 0.5  0 d
  O3    O2-    8 d 0.4899(7) 0.6870(7) 0.6509(4) 0.5  0 d
  O4    O2-    8 d 0.0246(6) 0.7478(5) 0.6987(4) 0.5  0 d
_refine_ls_R_factor_all            0.03