data_2003018
_journal_name_full     'Acta Crystallographica, Section B'
_journal_year     1998
_journal_volume     B54
_journal_page_first     851
_journal_page_last     858
loop_
_publ_author_name
    'Lenstra'
    'Bracke'
    'Van Dijk'
    'Maes'
    'Vanhulle'
    'Desseyn'
_chemical_formula_moiety     'C4 H6 N2 O2'
_chemical_formula_sum     'C4 H6 N2 O2'
_chemical_formula_weight     114.1
_symmetry_cell_setting     monoclinic
_symmetry_space_group_name_H-M     'P 21/c'
_symmetry_space_group_name_Hall     '-P 2ybc'
loop_
_symmetry_equiv_pos_as_xyz
 'x,y,z'
 '-x,y+1/2,-z+1/2'
 '-x,-y,-z'
 'x,-y+1/2,z+1/2'
_cell_length_a     5.941(3)
_cell_length_b     10.080(3)
_cell_length_c     8.282(2)
_cell_angle_alpha     90.0
_cell_angle_beta     95.87(3)
_cell_angle_gamma     90.0
_cell_volume     493.4(5)
_cell_formula_units_Z     4
_cell_measurement_reflns_used     25
_cell_measurement_theta_min     4
_cell_measurement_theta_max     16
_cell_measurement_temperature     293
_exptl_crystal_description     prism
_exptl_crystal_colour     colourless
_exptl_crystal_size_max     0.25
_exptl_crystal_size_mid     0.20
_exptl_crystal_size_min     0.15
_exptl_crystal_density_diffrn     1.536
_exptl_absorpt_coefficient_mu     0.12
_exptl_absorpt_correction_type     none
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_measurement_device     'Nonius CAD-4'
_diffrn_measurement_method     '\w-2\q'
_diffrn_reflns_number     1015
_diffrn_reflns_av_R_equivalents     0.03
_diffrn_reflns_theta_max     25
_diffrn_reflns_limit_h_min     0
_diffrn_reflns_limit_h_max     7
_diffrn_reflns_limit_k_min     0
_diffrn_reflns_limit_k_max     12
_diffrn_reflns_limit_l_min     -9
_diffrn_reflns_limit_l_max     9
_diffrn_standards_number     3
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     120
_diffrn_standards_decay_%     0
_reflns_number_total     1015
_reflns_number_observed     457
_reflns_observed_criterion     'I>3\s(I)'
_refine_ls_structure_factor_coef     F
_refine_ls_R_factor_obs     0.034
_refine_ls_wR_factor_obs     0.037
_refine_ls_number_reflns     457
_refine_ls_number_parameters     97
_refine_ls_shift/esd_max     0.05
_refine_diff_density_max     0.25
_refine_ls_extinction_method     'none'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
O1   .2785(3)   .0027(2)   .1096(3)
O2   .5621(3)   .1568(2)   .3128(3)
N1   .3552(3)   .3374(2)   .2296(3)
C2   .1642(4)   .3934(3)   .1291(4)
C3   -.0360(5)  .3046(3)   .1308(4)
N4   .0279(3)   .1705(2)   .0880(3)
C5   .2273(4)   .1182(3)   .1369(3)
C6   .3997(4)   .2073(3)   .2352(2)
H1   .459(4)   .389(3)    .278(3)
H4   -.075(4)  .117(3)    .032(3)
H21   .127(4)   .483(3)    .175(3)
H31   -.155(4)  .333(2)    .048(3)
H22   .203(4)   .407(3)    .019(3)
H32   -.093(4)  .300(3)    .237(3)