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_2104873
_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_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_cell_angle_alpha                58.32(2)
_cell_angle_beta                 148.78(2)
_cell_angle_gamma                127.30(2)
_cell_formula_units_Z            3
_cell_length_a                   19.497(4)
_cell_length_b                   5.2970(10)
_cell_length_c                   8.868(2)
_cell_measurement_reflns_used    2877
_cell_measurement_temperature    295
_cell_measurement_theta_max      30.5024
_cell_measurement_theta_min      2.820
_cell_volume                     377.6(3)
_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
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_exptl_absorpt_correction_T_min  0.1087
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'HABITUS (Herrendorf, 1997)'
_exptl_crystal_colour            orange
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_refine_ls_extinction_coef       970E1(11)
_refine_ls_extinction_method
'B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)'
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_refine_ls_R_factor_all          0.0271
_refine_ls_R_factor_gt           0.0269
_refine_ls_shift/su_max          0.0096
_refine_ls_shift/su_mean         0.0009
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     w=1/(\s^2^(F)+0.0001F^2^)
_refine_ls_weighting_scheme      sigma
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_reflns_threshold_expression     I>3\s(I)
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_cod_data_source_block           alpha-Ni2As2O7
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