data_global
_chemical_name_mineral 'Ice'
loop_
_publ_author_name
'Fortes A D'
'Wood I G'
'Grigoriev D'
'Alfredsson M'
'Kipfstuhl S'
'Knight K S'
'Smith R I'
_journal_name_full 'Journal of Chemical Physics'
_journal_volume 120 
_journal_year 2004
_journal_page_first 11376
_journal_page_last 11379
_publ_section_title
;
 No evidence for large-scale proton ordering in Antarctic ice from powder neutron diffraction
 Note: T = 100 K
 Note: known as ice-IH
;
_database_code_amcsd 0018366
_chemical_compound_source 'Kohen Station, Antarctica'
_chemical_formula_sum 'O H2'
_cell_length_a 4.497479
_cell_length_b 4.497479
_cell_length_c 7.322382
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 128.269
_exptl_crystal_density_diffrn      0.933
_symmetry_space_group_name_H-M 'P 63/m m c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-x+y,1/2+z'
  'x,x-y,1/2-z'
  '-x+y,-x,1/2-z'
  'x-y,x,1/2+z'
  '-y,-x,z'
  'y,x,-z'
  'y,-x+y,-z'
  '-y,x-y,z'
  'x-y,-y,1/2+z'
  '-x+y,y,1/2-z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  'x,x-y,z'
  '-x,-x+y,-z'
  'x-y,x,-z'
  '-x+y,-x,z'
  'y,x,1/2+z'
  '-y,-x,1/2-z'
  '-y,x-y,1/2-z'
  'y,-x+y,1/2+z'
  '-x+y,y,z'
  'x-y,-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
O   0.33333   0.66667   0.06140   1.00000
H1   0.33333   0.66667   0.19640   0.50000
H2   0.45100   0.90190   0.01790   0.50000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
O 0.00790 0.00790 0.00600 0.00400 0.00000 0.00000
H1 0.02110 0.02110 0.00820 0.01060 0.00000 0.00000
H2 0.01690 0.01240 0.01740 0.00620 0.00370 0.00750