Piperazine-2,5-dione–oxalic acid–water (1/1/2) and a redetermination of piperazine-2,5-dione, both at 120K: hydrogen-bonded sheets containing multiple ring types
Sarangarajan, Thanjavur Ramabhadran; Panchanatheswaran, Krishnaswamy; Low, John N.; Glidewell, Christopher; Acta Crystallographica Section C 61 (2005) o118–o121; doi:10.1107/S0108270104034055

data_2014742
_publ_section_title
;
 Piperazine-2,5-dione--oxalic acid--water (1/1/2) and a redetermination
 of piperazine-2,5-dione, both at 120K: hydrogen-bonded sheets
 containing multiple ring types
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o118
_journal_page_last               o121
_journal_paper_doi               10.1107/S0108270104034055
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C4 H6 N2 O2'
_chemical_formula_moiety         'C4 H6 N2 O2'
_chemical_formula_sum            'C4 H6 N2 O2'
_chemical_formula_weight         114.11
_chemical_name_systematic
;
2,5-Piperazinedione
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 96.46(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   3.8967(10)
_cell_length_b                   11.527(3)
_cell_length_c                   5.159(2)
_cell_measurement_reflns_used    508
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.46
_cell_measurement_theta_min      4.35
_cell_volume                     230.26(12)
_computing_cell_refinement       'DENZO--SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'program (reference)?'
_computing_data_reduction        DENZO--SMN
_computing_molecular_graphics    'PLATON (Spek, 2003)'
_computing_publication_material  'SHELXL97 and PRPKAPPA (Ferguson, 1999)'
_computing_structure_refinement  'OSCAIL and SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution
'OSCAIL (McArdle , 2003) and SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.971
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       '\f scans, and \w scans with \k offsets'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1053
_diffrn_reflns_av_sigmaI/netI    0.0525
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            2525
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         27.46
_diffrn_reflns_theta_min         4.35
_diffrn_standards_decay_%        nil
_exptl_absorpt_coefficient_mu    0.134
_exptl_absorpt_correction_T_max  0.992
_exptl_absorpt_correction_T_min  0.935
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SORTAV; Blessing, 1995, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.646
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             120
_exptl_crystal_size_max          0.58
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.475
_refine_diff_density_min         -0.489
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.245
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     37
_refine_ls_number_reflns         508
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.245
_refine_ls_R_factor_all          0.0677
_refine_ls_R_factor_gt           0.0670
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1311P)^2^+0.0775P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2049
_refine_ls_wR_factor_ref         0.2060
_reflns_number_gt                490
_reflns_number_total             508
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1802.cif
_cod_data_source_block           II
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'Multi-scan' changed to
'multi-scan' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2014742
_cod_database_fobs_code          2014742