Exploiting superspace to clarify vacancy and Al/Si ordering in mullite
Klar, Paul Benjamin; Etxebarria, Iñigo; Madariaga, Gotzon; IUCrJ 5 (2018) –; doi:10.1107/S2052252518007467

data_1549598
_publ_section_title
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 Exploiting superspace to clarify vacancy and Al/Si ordering in mullite
;
_journal_coeditor_code           GQ5008
_journal_issue                   4
_journal_name_full               IUCrJ
_journal_page_first
;
;
_journal_paper_doi               10.1107/S2052252518007467
_journal_volume                  5
_journal_year                    2018
_chemical_compound_source        'Sigma Aldrich'
_chemical_formula_sum            'Al4.857 O9.571 Si1.143'
_chemical_formula_weight         316.3
_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                   7.5787(7)
_cell_length_b                   7.6707(4)
_cell_length_c                   2.88360(10)
_cell_measurement_reflns_used    2027
_cell_measurement_temperature    293
_cell_measurement_theta_max      31.88
_cell_measurement_theta_min      4.06
_cell_modulation_dimension       1
_cell_volume                     167.635(19)
_computing_cell_refinement       'CrysAlisPro 1.171.38.46 (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.46 (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.46 (Rigaku OD, 2015)'
_computing_structure_refinement  Jana2006
_diffrn_ambient_temperature      293
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 5.8
_diffrn_measured_fraction_theta_full 0.95
_diffrn_measured_fraction_theta_max 0.77
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type
'dectris-CrysAlisPro-abstract goniometer imported dectris images'
_diffrn_measurement_method       '\w scans'
_diffrn_measurement_specimen_support 'polymer loop'
_diffrn_radiation_monochromator  synchrotron
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.7231
_diffrn_reflns_av_R_equivalents  0.0137
_diffrn_reflns_av_unetI/netI     0.0034
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_index_m_1_max 1
_diffrn_reflns_limit_index_m_1_min -1
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       4
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            3363
_diffrn_reflns_theta_full        23.49
_diffrn_reflns_theta_max         32.02
_diffrn_reflns_theta_min         3.85
_diffrn_source                   synchrotron
_exptl_absorpt_coefficient_mu    1.08
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.834
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.46 (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.133
_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         0.37
_refine_diff_density_min         -0.33
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_gt    1.12
_refine_ls_goodness_of_fit_ref   1.01
_refine_ls_number_constraints    33
_refine_ls_number_parameters     101
_refine_ls_number_reflns         678
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0384
_refine_ls_R_factor_gt           0.0371
_refine_ls_shift/su_max          0.0003
_refine_ls_shift/su_mean         0.0000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     w=1/(\s^2^(I)+0.0081000002I^2^)
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_gt          0.1028
_refine_ls_wR_factor_ref         0.1044
_reflns_number_gt                555
_reflns_number_total             678
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            gq5008.cif
_cod_data_source_block           SA1
_cod_database_code               1549598