Crystal structure of 2,2'-biimidazolium bis- (dihydrogen phosphate), [C6H8N4][H2PO4]2
Geng-Xu Yang; Shi-Zhen Zhang; Zi-Liang Wang; Zeitschrift für Kristallographie - New Crystal Structures 225 (2010) 127–; doi:

data_8102607
_publ_contact_author
;
  Ziliang Wang     
;
_publ_section_title
;
 Crystal structure of 2,2'-biimidazolium bis- (dihydrogen phosphate),
 [C6H8N4][H2PO4]2
;
_journal_issue                   1
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              127
_journal_volume                  225
_journal_year                    2010
_chemical_formula_moiety         'C6 H8 N4, 2(H2 O4 P)'
_chemical_formula_sum            'C6 H12 N4 O8 P2'
_chemical_formula_weight         330.14
_chemical_name_systematic
; 
(C~6~H~8~N~4~^2+^).2(H~2~PO~4~^-^)
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 107.858(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.903(2)
_cell_length_b                   9.6799(12)
_cell_length_c                   8.4361(11)
_cell_measurement_reflns_used    2273
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      28.05
_cell_measurement_theta_min      2.50
_cell_volume                     1236.1(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick,1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick,1997)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker SMART Apex CCD area-detector'
_diffrn_measurement_method       '0.3\% wide \w exposures'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0773
_diffrn_reflns_av_sigmaI/netI    0.0464
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3962
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.50
_exptl_absorpt_coefficient_mu    0.400
_exptl_absorpt_correction_T_max  0.9842
_exptl_absorpt_correction_T_min  0.9462
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.774
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             680
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.419
_refine_diff_density_min         -0.368
_refine_diff_density_rms         0.074
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.094
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     107
_refine_ls_number_reflns         1080
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.092
_refine_ls_R_factor_all          0.0402
_refine_ls_R_factor_gt           0.0373
_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^)+(0.0422P)^2^+1.2435P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0953
_refine_ls_wR_factor_ref         0.0970
_reflns_number_gt                993
_reflns_number_total             1080
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            1267-2837.cff
_cod_data_source_block           global
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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_enum 1555 2011-01-17 13:19:09Z saulius 
;
_cod_original_cell_volume        1236.0(3)
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               8102607