data_global
_chemical_name_mineral 'Urea'
loop_
_publ_author_name
'Worsham J'
'Levy H'
'Peterson S'
_journal_name_full 'Acta Crystallographica'
_journal_volume 10 
_journal_year 1957
_journal_page_first 319
_journal_page_last 323
_publ_section_title
;
 The positions of hydrogen atoms in urea by neutron diffraction
 _cod_database_code 1008776
;
_database_code_amcsd 0016652
_chemical_formula_sum 'C O N2 H4'
_cell_length_a 5.661
_cell_length_b 5.661
_cell_length_c 4.712
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 151.005
_exptl_crystal_density_diffrn      1.321
_symmetry_space_group_name_H-M 'P -4 21 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2-y,1/2-x,z'
  'y,-x,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,z'
  '1/2+y,1/2+x,z'
  '-y,x,-z'
  '1/2+x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
C1   0.00000   0.50000   0.33300
O1   0.00000   0.50000   0.59680
N1   0.14390   0.64390   0.18320
H1   0.25220   0.75220   0.28390
H2   0.13650   0.63650   0.97240
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
C1 3.81526 3.81526 0.95609 0.00000 0.00000 0.00000
O1 6.07195 6.07195 0.89985 0.00000 0.00000 0.00000
N1 7.89029 7.89029 1.56349 0.00000 -0.09459 -0.09459
H1 10.27685 10.27685 3.98184 0.00000 -0.45946 -0.45946
H2 10.91002 10.91002 2.04716 0.00000 -0.31081 -0.31081