Piperazinium bis(dihydrogenarsenate)
Wilkinson, Hazel S.; Harrison, William T. A.; Acta Crystallographica Section E 63 (2007) m26–m28; doi:10.1107/S160053680605118X

data_2211730
_publ_section_title
;
 Piperazinium bis(dihydrogenarsenate)
;
_journal_coeditor_code           BI2109
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              m26
_journal_page_last               m28
_journal_paper_doi               10.1107/S160053680605118X
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C4 H12 N2 2+, 2H2 As O4 -'
_chemical_formula_moiety         'C4 H12 N2 2+, 2(H2 As O4 -)'
_chemical_formula_sum            'C4 H16 As2 N2 O8'
_chemical_formula_weight         370.02
_chemical_name_systematic
;
Piperazinium bis(dihydrogenarsenate)
;
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 95.1260(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   5.8208(3)
_cell_length_b                   8.9966(4)
_cell_length_c                   11.0369(5)
_cell_measurement_reflns_used    4016
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      32.51
_cell_measurement_theta_min      2.28
_cell_volume                     575.66(5)
_computing_cell_refinement       'SAINT (Bruker, 1999)'
_computing_data_collection       'SMART (Bruker, 1999)'
_computing_data_reduction        SAINT
_computing_molecular_graphics
'ORTEP-3 (Farrugia, 1997) and ATOMS (Shape Software, 2004)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker SMART1000 CCD'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0192
_diffrn_reflns_av_sigmaI/netI    0.0172
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            5723
_diffrn_reflns_theta_full        32.51
_diffrn_reflns_theta_max         32.51
_diffrn_reflns_theta_min         2.93
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    5.835
_exptl_absorpt_correction_T_max  0.277
_exptl_absorpt_correction_T_min  0.141
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 1999)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.135
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             368
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.41
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.544
_refine_diff_density_min         -0.496
_refine_ls_extinction_coef       0.061(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     74
_refine_ls_number_reflns         2081
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0220
_refine_ls_R_factor_gt           0.0184
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0302P)^2^+0.0622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0494
_refine_ls_wR_factor_ref         0.0504
_reflns_number_gt                1843
_reflns_number_total             2081
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bi2109.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2211730
_cod_database_fobs_code          2211730