data_global
_chemical_name_mineral 'Wesselsite'
loop_
_publ_author_name
'Knight K S'
'Henderson C M B'
_journal_name_full 'European Journal of Mineralogy'
_journal_volume 19 
_journal_year 2007
_journal_page_first 189
_journal_page_last 200
_publ_section_title
;
 Structural basis for the anomalous low-temperature thermal expansion
 behavior of the gillespite-structured phase Ba0.5Sr0.5CuSi4O10
 Sample: T = 25 K
;
_database_code_amcsd 0007208
_chemical_formula_sum '(Ba.5 Sr.5) Cu Si4 O10'
_cell_length_a 7.39640
_cell_length_b 7.39640
_cell_length_c 15.8466
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 866.916
_exptl_crystal_density_diffrn      3.435
_symmetry_space_group_name_H-M 'P 4/n c c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2-y,1/2-x,1/2+z'
  '1/2+y,1/2+x,1/2-z'
  '1/2+y,-x,-z'
  '1/2-y,x,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '1/2+x,1/2+y,-z'
  '1/2-x,1/2-y,z'
  'y,x,1/2+z'
  '-y,-x,1/2-z'
  '-y,1/2+x,-z'
  'y,1/2-x,z'
  '1/2-x,y,1/2+z'
  '1/2+x,-y,1/2-z'
  '-x,-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
Ba   0.25000   0.75000   0.00000   0.50000   0.02510
Sr   0.25000   0.75000   0.00000   0.50000   0.02510
Cu   0.25000   0.25000   0.09136   1.00000   0.04690
Si   0.51220   0.93340   0.15173   1.00000   0.02540
O1   0.45450   0.98400   0.24590   0.50000   0.05540
O2   0.71770  -0.00020   0.13312   1.00000   0.05410
O3   0.37360   0.02340   0.08812   1.00000   0.06640