#------------------------------------------------------------------------------
#$Date: 2016-02-18 17:37:37 +0200 (Thu, 18 Feb 2016) $
#$Revision: 176729 $
#$URL: svn://www.crystallography.net/cod/cif/1/50/68/1506836.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_1506836
loop_
_publ_author_name
'Vishweshwar, Peddy'
'Jagadeesh Babu, N.'
'Nangia, Ashwini'
'Mason, Sax A.'
'Puschmann, Horst'
'Mondal, Raju'
'Howard, Judith A. K.'
_publ_section_title
;
 Variable Temperature Neutron Diffraction Analysis of a Very Short
 O−H···O Hydrogen Bond in
 2,3,5,6-Pyrazinetetracarboxylic Acid Dihydrate:  Synthon-Assisted
 Short Oacid−H···OwaterHydrogen Bonds in a
 Multicenter Array
;
_journal_issue                   43
_journal_name_full               'The Journal of Physical Chemistry A'
_journal_page_first              9406
_journal_paper_doi               10.1021/jp0476848
_journal_volume                  108
_journal_year                    2004
_chemical_formula_moiety         'C8 H4 N2 O8, 2H2O'
_chemical_formula_sum            'C8 H8 N2 O10'
_chemical_formula_weight         292.16
_chemical_melting_point          480
_chemical_name_common
;
2,3,5,6-pyrazinetetracarboxylic acid dihydrate
;
_chemical_name_systematic
; 
 2,3,5,6-pyrazinetetracarboxylic acid dihydrate
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                99.393(6)
_cell_angle_beta                 107.565(7)
_cell_angle_gamma                105.174(7)
_cell_formula_units_Z            1
_cell_length_a                   5.4950(10)
_cell_length_b                   6.4410(10)
_cell_length_c                   8.7670(10)
_cell_measurement_reflns_used    577
_cell_measurement_temperature    293(1)
_cell_measurement_theta_max      31.65
_cell_measurement_theta_min      4.02
_cell_volume                     275.44(8)
_computing_cell_refinement       'ILL RAFD9'
_computing_data_collection       'ILL HKLGEN, MAD'
_computing_data_reduction        'ILL RACER'
_computing_molecular_graphics    'ORTEP and PLUTON'
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(1)
_diffrn_detector_area_resol_mean '0.25 degrees'
_diffrn_measured_fraction_theta_full 0.970
_diffrn_measured_fraction_theta_max 0.970
_diffrn_measurement_device_type  'd9 four-circle diffractometer'
_diffrn_measurement_method       'omega step-scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          neutron
_diffrn_radiation_source         'ILL reactor'
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.83970
_diffrn_reflns_av_R_equivalents  0.0136
_diffrn_reflns_av_sigmaI/netI    0.0191
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            1295
_diffrn_reflns_theta_full        32.08
_diffrn_reflns_theta_max         32.08
_diffrn_reflns_theta_min         2.98
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.000
_exptl_absorpt_correction_T_max  0.9409
_exptl_absorpt_correction_T_min  0.8570
_exptl_absorpt_correction_type   'Gaussian grid'
_exptl_absorpt_process_details   'program DATAP'
_exptl_crystal_colour            'Pale yellow'
_exptl_crystal_density_diffrn    1.760
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             100
_exptl_crystal_size_max          2.8
_exptl_crystal_size_mid          1.6
_exptl_crystal_size_min          0.6
_refine_diff_density_max         0.317
_refine_diff_density_min         -0.374
_refine_diff_density_rms         0.068
_refine_ls_extinction_coef       0.075(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.123
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     135
_refine_ls_number_reflns         1122
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.123
_refine_ls_R_factor_all          0.0253
_refine_ls_R_factor_gt           0.0219
_refine_ls_shift/su_max          0.912
_refine_ls_shift/su_mean         0.017
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[σ²(Fo²)+(0.0147P)²+0.3156P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0453
_refine_ls_wR_factor_ref         0.0468
_reflns_number_gt                1040
_reflns_number_total             1122
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jp0476848si20040528_030418.cif
_cod_data_source_block           a
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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_cell_volume        275.44(7)
_cod_database_code               1506836
loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-x, -y, -z'
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
O1 O 0.2546(2) -0.05271(16) 0.09102(11) 0.0308(4) Uani 1.000(6) 1 d .
O14 O 0.1829(2) 0.28935(16) 0.22033(12) 0.0296(5) Uani 1.000(7) 1 d .
O3 O 0.6289(2) 0.00271(17) 0.30634(12) 0.0368(3) Uani 1 1 d .
O4 O 0.7478(2) -0.3812(2) 0.44300(12) 0.0459(3) Uani 1 1 d .
O5 O 1.0901(2) -0.2204(2) 0.36979(12) 0.0405(5) Uani 1.000(7) 1 d .
N7 N 0.31246(10) -0.40556(8) -0.07606(6) 0.02064(16) Uani 1 1 d .
H2 H 0.2342(4) 0.0909(3) 0.1559(2) 0.0380(7) Uani 0.996(10) 1 d P
H5 H 1.1958(4) -0.1676(4) 0.4896(2) 0.0526(8) Uani 1.000(11) 1 d .
C8 C 0.45918(15) -0.10377(12) 0.17233(8) 0.02152(18) Uani 1 1 d .
C9 C 0.47762(14) -0.31531(11) 0.08175(8) 0.01880(17) Uani 1 1 d .
C10 C 0.66599(14) -0.41138(11) 0.15872(8) 0.01903(18) Uani 1 1 d .
C11 C 0.83927(15) -0.33106(12) 0.34098(8) 0.02243(18) Uani 1 1 d .
H12 H 0.2210(5) 0.3301(4) 0.3376(2) 0.0554(9) Uani 0.996(12) 1 d P
H13 H 0.0036(4) 0.2895(3) 0.1664(2) 0.0434(8) Uani 0.995(12) 1 d P
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_23
_atom_site_aniso_U_13
_atom_site_aniso_U_12
O1 0.0334(6) 0.0316(6) 0.0203(5) -0.0025(4) -0.0011(4) 0.0175(4)
O14 0.0299(8) 0.0330(5) 0.0208(7) -0.0016(4) 0.0024(5) 0.0154(4)
O3 0.0353(5) 0.0350(5) 0.0216(4) -0.0116(4) -0.0073(4) 0.0141(4)
O4 0.0408(6) 0.0641(7) 0.0140(4) 0.0060(4) 0.0036(4) -0.0030(5)
O5 0.0242(6) 0.0595(7) 0.0176(7) -0.0013(4) -0.0016(4) -0.0007(5)
N7 0.0222(3) 0.0221(3) 0.0118(2) 0.00002(17) -0.00045(18) 0.00846(19)
H2 0.0411(10) 0.0389(10) 0.0294(9) 0.0023(7) 0.0060(6) 0.0179(7)
H5 0.0362(11) 0.0712(14) 0.0247(12) -0.0021(8) -0.0049(8) 0.0042(9)
C8 0.0232(4) 0.0218(3) 0.0137(3) -0.0014(2) 0.0012(3) 0.0080(3)
C9 0.0203(3) 0.0198(3) 0.0110(3) -0.0001(2) 0.0005(2) 0.0068(3)
C10 0.0203(3) 0.0206(3) 0.0102(3) 0.0000(2) -0.0004(2) 0.0066(3)
C11 0.0236(4) 0.0257(3) 0.0102(3) 0.0000(2) -0.0008(3) 0.0067(3)
H12 0.0660(15) 0.0677(14) 0.0263(14) -0.0020(8) 0.0035(8) 0.0363(11)
H13 0.0354(14) 0.0518(11) 0.0386(11) 0.0070(7) 0.0059(9) 0.0191(8)
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
N N 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
C8 O1 H2 113.93(12) .
H2 O14 H12 116.56(17) .
H2 O14 H13 114.32(16) .
H12 O14 H13 107.0(2) .
C11 O5 H5 111.07(16) .
C10 N7 C9 118.00(5) 2_645
O3 C8 O1 126.26(8) .
O3 C8 C9 120.41(8) .
O1 C8 C9 113.32(7) .
N7 C9 C10 120.99(6) .
N7 C9 C8 117.67(6) .
C10 C9 C8 121.32(6) .
N7 C10 C9 121.00(6) 2_645
N7 C10 C11 115.22(6) 2_645
C9 C10 C11 123.57(6) .
O4 C11 O5 125.80(9) .
O4 C11 C10 120.75(8) .
O5 C11 C10 113.29(7) .
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
O1 C8 1.2909(12) .
O1 H2 1.0551(18) .
O14 H2 1.4425(19) .
O14 H12 0.960(2) .
O14 H13 0.956(3) .
O3 C8 1.2088(12) .
O4 C11 1.1990(14) .
O5 C11 1.2996(14) .
O5 H5 0.9841(19) .
N7 C10 1.3325(9) 2_645
N7 C9 1.3339(8) .
C8 C9 1.5050(9) .
C9 C10 1.3999(10) .
C10 N7 1.3324(9) 2_645
C10 C11 1.5105(9) .
