data_global
_chemical_name_mineral 'Ice II'
loop_
_publ_author_name
'McFarlan R'
_journal_name_full 'Journal of Chemical Physics'
_journal_volume 4 
_journal_year 1936
_journal_page_first 60
_journal_page_last 64
_publ_section_title
;
 The Structure of Ice II
 _cod_database_code 1011063
;
_database_code_amcsd 0017962
_chemical_formula_sum 'O H2'
_cell_length_a 7.8
_cell_length_b 4.5
_cell_length_c 5.56
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 195.156
_exptl_crystal_density_diffrn      1.226
_symmetry_space_group_name_H-M 'C 2 2 21'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-z'
  'x,-y,-z'
  '1/2+x,1/2-y,-z'
  '-x,-y,1/2+z'
  '1/2-x,1/2-y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
O1   0.16700   0.20500   0.17800
H1   0.16700   0.00000   0.00000
H2   0.00000   0.25000   0.25000
H3   0.25000   0.45500   0.25000