Ordered vacancy distribution in 2/1 mullite: a superspace model
Klar, Paul B.; de la Pinta, Noelia; Lopez, Gabriel A.; Etxebarria, Iñigo; Breczewski, Tomasz; Madariaga, Gotzon; Acta Crystallographica Section B 73 (2017) –; doi:10.1107/S2052520617001652

data_2108042
_publ_section_title
;
 Ordered vacancy distribution in 2/1 mullite: a superspace model
;
_journal_coeditor_code           DQ5021SUP1
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first
;
;
_journal_paper_doi               10.1107/S2052520617001652
_journal_volume                  73
_journal_year                    2017
_chemical_compound_source        'Sigma Aldrich'
_chemical_formula_moiety         '2.1(Al2 O3), (Si O2)'
_chemical_formula_sum            'Al4.847 O9.577 Si1.153'
_chemical_formula_weight         316.4
_chemical_name_common            Mullite
_space_group_IT_number           55
_space_group_ssg_name            Pbam(\a01/2)0ss
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2 2ab'
_symmetry_space_group_name_H-M   'P b a m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            1
_cell_length_a                   7.5817(6)
_cell_length_b                   7.6752(7)
_cell_length_c                   2.8843(3)
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_cell_measurement_temperature    293
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_cell_modulation_dimension       1
_cell_volume                     167.84(3)
_computing_cell_refinement       'STOE X-Area'
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_computing_molecular_graphics    VESTA3
_computing_structure_refinement  'Jana 2006'
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_diffrn_ambient_temperature      293
_diffrn_detector                 'DECTRIS Pilatus 100K'
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_diffrn_measured_fraction_theta_full 0.98
_diffrn_measured_fraction_theta_max 0.54
_diffrn_measurement_device       'four circle diffractometer'
_diffrn_measurement_device_type  'STOE Stadi Vari'
_diffrn_measurement_method       'integration technique, STOE X-Area'
_diffrn_measurement_specimen_support 'polymer loop'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0505
_diffrn_reflns_av_unetI/netI     0.0236
_diffrn_reflns_limit_h_max       13
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_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            3095
_diffrn_reflns_theta_full        25.47
_diffrn_reflns_theta_max         39.5
_diffrn_reflns_theta_min         3.77
_diffrn_source                   'GeniX 3D Microfocus Source'
_diffrn_source_current           1
_diffrn_source_power             0.05
_diffrn_source_voltage           50
_exptl_absorpt_coefficient_mu    1.06
_exptl_absorpt_correction_T_max  0.9810
_exptl_absorpt_correction_T_min  0.9650
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'STOE X-Red32'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.1302
_exptl_crystal_description       'irregularly shaped block'
_exptl_crystal_F_000             156
_exptl_crystal_size_max          0.056
_exptl_crystal_size_mid          0.051
_exptl_crystal_size_min          0.034
_exptl_crystal_size_rad          0.029
_refine_diff_density_max         1.18
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_refine_ls_extinction_method     none
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_refine_ls_goodness_of_fit_ref   0.98
_refine_ls_hydrogen_treatment    constr
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_refine_ls_number_parameters     52
_refine_ls_number_reflns         864
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0629
_refine_ls_R_factor_gt           0.0354
_refine_ls_shift/su_max          0.0008
_refine_ls_shift/su_mean         0.0001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     w=1/(\s^2^(I)+0.0049000001I^2^)
_refine_ls_weighting_scheme      sigma
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_refine_ls_wR_factor_ref         0.1115
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_reflns_number_total             864
_reflns_threshold_expression     I>3\s(I)
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_cod_database_fobs_code 2108042