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_2104871
_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     'Mn2 As2 O7'
_chemical_formula_sum            'As2 Mn2 O7'
_chemical_formula_weight         371.7
_chemical_name_systematic
;
Dimanganese(II) diarsenate(V)
;
_space_group_IT_number           12
_symmetry_cell_setting           monoclinic
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_symmetry_space_group_name_H-M   'C 1 2/m 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 102.723(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.7454(8)
_cell_length_b                   8.7561(10)
_cell_length_c                   4.8004(7)
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_cell_measurement_temperature    295
_cell_measurement_theta_max      16.563
_cell_measurement_theta_min      10.161
_cell_volume                     276.57(6)
_computing_cell_refinement       CAD-4
_computing_data_collection       'CAD-4 (Nonius, 1989)'
_computing_data_reduction        'HELENA implemented in PLATON (Spek, 2009)'
_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-circle diffractometer'
_diffrn_measurement_device_type  'Nonius CAD-4'
_diffrn_measurement_method       \q/2\q-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0395
_diffrn_reflns_av_sigmaI/netI    0.0094
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
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_diffrn_reflns_theta_max         41.92
_diffrn_reflns_theta_min         3.87
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    16.421
_exptl_absorpt_correction_T_max  0.2223
_exptl_absorpt_correction_T_min  0.0613
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'HABITUS (Herrendorf, 1997)'
_exptl_crystal_colour            'light pink'
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_exptl_crystal_description       'trigonal plate'
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_exptl_crystal_size_max          0.288
_exptl_crystal_size_mid          0.288
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_refine_diff_density_max         3.39
_refine_diff_density_min         -3.00
_refine_ls_extinction_coef       85E2(3)
_refine_ls_extinction_method
'B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)'
_refine_ls_goodness_of_fit_ref   3.26
_refine_ls_number_constraints    0
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_refine_ls_R_factor_all          0.0388
_refine_ls_R_factor_gt           0.0365
_refine_ls_shift/su_max          0.0006
_refine_ls_shift/su_mean         0.0001
_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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_cod_data_source_file            sn5100.cif
_cod_data_source_block           Mn2As2O7
_cod_original_sg_symbol_H-M      'C 2/m'
_cod_database_code               2104871
_cod_database_fobs_code          2104871