Cyclobutane-1,2-dione
Betz, Richard; Klüfers, Peter; Acta Crystallographica Section E 63 (2007) o3981–o3981; doi:10.1107/S1600536807042924

data_2215601
_publ_section_title
;
 Cyclobutane-1,2-dione
;
_journal_coeditor_code           NC2049
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o3981
_journal_page_last               o3981
_journal_paper_doi               10.1107/S1600536807042924
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C4 H4 O2'
_chemical_formula_moiety         'C4 H4 O2'
_chemical_formula_sum            'C4 H4 O2'
_chemical_formula_weight         84.07
_chemical_name_common            Cyclobutane-1,2-dione
_chemical_name_systematic
;
Cyclobutane-1,2-dione
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.3719(3)
_cell_length_b                   6.8819(3)
_cell_length_c                   10.8378(6)
_cell_measurement_reflns_used    5161
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      27.485
_cell_measurement_theta_min      3.134
_cell_volume                     400.66(4)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor, 1997)'
_computing_data_collection       'Collect (Bruker--Nonius, 2004)'
_computing_data_reduction
'HKL Denzo and Scalepack (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'ORTEPIII (Burnett & Johnson, 1996)'
_computing_publication_material  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device       '95mm CCD camera on \k-goniostat'
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       'CCD; rotation images; thick slices'
_diffrn_radiation_monochromator  'MONTEL, graded multilayered X-ray optics'
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0384
_diffrn_reflns_av_sigmaI/netI    0.0249
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            3074
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         3.51
_exptl_absorpt_coefficient_mu    0.113
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow--orange
_exptl_crystal_density_diffrn    1.394
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             176
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.118
_refine_diff_density_min         -0.146
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.088
_refine_ls_hydrogen_treatment    refU
_refine_ls_matrix_type           full
_refine_ls_number_parameters     56
_refine_ls_number_reflns         557
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.088
_refine_ls_R_factor_all          0.0386
_refine_ls_R_factor_gt           0.0307
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0567P)^2^+0.2940P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0750
_refine_ls_wR_factor_ref         0.0812
_reflns_number_gt                488
_reflns_number_total             557
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            nc2049.cif
_cod_data_source_block           I
_cod_database_code               2215601
_cod_database_fobs_code          2215601