Crystal chemistry of transition metal diarsenates <i>M</i>~2~As~2~O~7~ (<i>M</i> = Mn, Co, Ni, Zn): variants of the thortveitite structure
Weil, Matthias; Stöger, Berthold; Acta Crystallographica Section B 66 (2010) 603–614; doi:10.1107/S0108768110040802

data_2104863
_publ_section_title
;
 Crystal chemistry of transition metal diarsenates <i>M</i>~2~As~2~O~7~
 (<i>M</i> = Mn, Co, Ni, Zn): variants of the thortveitite structure
;
_journal_coeditor_code           SN5100
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              603
_journal_page_last               614
_journal_paper_doi               10.1107/S0108768110040802
_journal_volume                  66
_journal_year                    2010
_chemical_formula_structural     'Ni2 As2 O7'
_chemical_formula_sum            'As2 Ni2 O7'
_chemical_formula_weight         379.2
_chemical_name_systematic        ' Dinickel(II) diarsenate(V)'
_space_group_ssg_name            C1(\a\b\g)0
_symmetry_cell_setting           triclinic
_cell_angle_alpha                89.19(7)
_cell_angle_beta                 103.28(5)
_cell_angle_gamma                89.46(3)
_cell_formula_units_Z            2
_cell_length_a                   6.499
_cell_length_b                   8.4276
_cell_length_c                   4.7223
_cell_measurement_reflns_used    2877
_cell_measurement_temperature    295
_cell_measurement_theta_max      30.5024
_cell_measurement_theta_min      2.820
_cell_modulation_dimension       1
_cell_volume                     251.68(5)
_computing_cell_refinement       'SAINT (Bruker, 2004)'
_computing_data_collection       'SMART (Bruker, 2004)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'ATOMS (Dowty, 2006)'
_computing_publication_material
'Jana2006 (Petricek, Dusek & Palatinus, 2006)'
_computing_structure_refinement
'Jana2006 (Petricek, Dusek & Palatinus, 2006)'
_computing_structure_solution    'SHELXS (Sheldrick, 2008)'
_diffrn_ambient_temperature      295
_diffrn_measured_fraction_theta_full 0.99
_diffrn_measured_fraction_theta_max 0.99
_diffrn_measurement_device       'four-cycle diffractometer'
_diffrn_measurement_device_type  'Bruker SMART CCD'
_diffrn_measurement_method       \w-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.067
_diffrn_reflns_av_sigmaI/netI    0.0268
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
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_diffrn_reflns_limit_index_m_1_min -1
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -7
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_diffrn_reflns_theta_full        32.54
_diffrn_reflns_theta_max         32.54
_diffrn_reflns_theta_min         2.16
_exptl_absorpt_coefficient_mu    20.508
_exptl_absorpt_correction_T_max  0.5542
_exptl_absorpt_correction_T_min  0.1087
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'HABITUS (Herrendorf, 1997)'
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    5.0024
_exptl_crystal_description       plate
_exptl_crystal_F_000             356
_exptl_crystal_size_max          0.230
_exptl_crystal_size_mid          0.180
_exptl_crystal_size_min          0.082
_refine_diff_density_max         1.40
_refine_diff_density_min         -0.71
_refine_ls_extinction_coef       970E1(11)
_refine_ls_extinction_method
'B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)'
_refine_ls_goodness_of_fit_ref   1.76
_refine_ls_number_constraints    3
_refine_ls_number_parameters     296
_refine_ls_number_reflns         5394
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0271
_refine_ls_R_factor_gt           0.0269
_refine_ls_shift/su_max          0.0119
_refine_ls_shift/su_mean         0.0015
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     w=1/(\s^2^(F)+0.0001F^2^)
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_gt          0.0316
_refine_ls_wR_factor_ref         0.0317
_reflns_number_gt                5331
_reflns_number_total             5394
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            sn5100.cif
_cod_data_source_block           alpha-Ni2As2O7-superspace
_cod_original_cell_volume        251.7(3)
_cod_database_code               2104863
_cod_database_fobs_code          2104863