data_global
_chemical_name_mineral 'Marshite'
loop_
_publ_author_name
'Hull S'
'Keen D A'
_journal_name_full 'Physical Review'
_journal_volume B50 
_journal_year 1994
_journal_page_first 5868
_journal_page_last 5885
_publ_section_title
;
 High-pressure polymorphism of the copper(I) halides:
 A neutron-diffraction study to ~10 GPa
 Note: P = 3.60 GPa
 Note: known as CuI-IV
;
_database_code_amcsd 0015182
_chemical_formula_sum 'Cu I'
_cell_length_a 4.0826
_cell_length_b 4.0826
_cell_length_c 20.077
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 289.803
_exptl_crystal_density_diffrn      6.548
_symmetry_space_group_name_H-M 'R -3 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'x,x-y,z'
  '2/3+x,1/3+x-y,1/3+z'
  '1/3+x,2/3+x-y,2/3+z'
  'y,x,-z'
  '2/3+y,1/3+x,1/3-z'
  '1/3+y,2/3+x,2/3-z'
  '-x+y,y,z'
  '2/3-x+y,1/3+y,1/3+z'
  '1/3-x+y,2/3+y,2/3+z'
  '-x,-x+y,-z'
  '2/3-x,1/3-x+y,1/3-z'
  '1/3-x,2/3-x+y,2/3-z'
  '-y,-x,z'
  '2/3-y,1/3-x,1/3+z'
  '1/3-y,2/3-x,2/3+z'
  'x-y,-y,-z'
  '2/3+x-y,1/3-y,1/3-z'
  '1/3+x-y,2/3-y,2/3-z'
  'y,-x+y,-z'
  '2/3+y,1/3-x+y,1/3-z'
  '1/3+y,2/3-x+y,2/3-z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
  '-x,-y,-z'
  '2/3-x,1/3-y,1/3-z'
  '1/3-x,2/3-y,2/3-z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  'x-y,x,-z'
  '2/3+x-y,1/3+x,1/3-z'
  '1/3+x-y,2/3+x,2/3-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Cu   0.00000   0.00000   0.12820   0.02875
I1   0.00000   0.00000   0.00000   0.01950
I2   0.00000   0.00000   0.50000   0.01950