The modulated average structure of mullite.
Birkenstock, Johannes; Petříček, Václav; Pedersen, Bjoern; Schneider, Hartmut; Fischer, Reinhard X.; Acta Crystallographica, Section B: Structural Science, Crystal Engineering and Materials 71 (2015) 358–368; doi:10.1107/S205252061500757X

data_2310785
_publ_section_title
;
 The modulated average structure of mullite.
;
_journal_coden_ASTM              ACSBDA
_journal_coeditor_code           WF5116
_journal_issue                   3
_journal_name_full
;
 Acta Crystallographica, Section B: Structural Science, Crystal Engineering
 and Materials
;
_journal_page_first              358
_journal_page_last               368
_journal_paper_doi               10.1107/S205252061500757X
_journal_volume                  71
_journal_year                    2015
_chemical_formula_sum            'Al4.8 O9.6 Si1.2'
_chemical_formula_weight         316.8
_chemical_name_systematic        ' ?'
_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                   7.5911
_cell_length_b                   7.6924
_cell_length_c                   2.8899
_cell_measurement_temperature    293
_cell_modulation_dimension       1
_cell_volume                     168.752
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_full 0.98
_diffrn_measured_fraction_theta_max 0.94
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Bruker CCD'
_diffrn_measurement_method       'integration technique'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0284
_diffrn_reflns_av_unetI/netI     0.0107
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_index_m_1_max 1
_diffrn_reflns_limit_index_m_1_min -1
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            8049
_diffrn_reflns_theta_full        35.56
_diffrn_reflns_theta_max         36.57
_diffrn_reflns_theta_min         3.98
_exptl_absorpt_coefficient_mu    1.057
_exptl_absorpt_correction_T_max  0.8306
_exptl_absorpt_correction_T_min  0.7414
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.1174
_exptl_crystal_description       'stump wedge'
_exptl_crystal_F_000             156
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.39
_refine_diff_density_min         -0.50
_refine_ls_extinction_coef       2000(200)
_refine_ls_extinction_method
'B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)'
_refine_ls_goodness_of_fit_gt    3.82
_refine_ls_goodness_of_fit_ref   3.01
_refine_ls_number_constraints    48
_refine_ls_number_parameters     106
_refine_ls_number_reflns         1234
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0461
_refine_ls_R_factor_gt           0.0277
_refine_ls_shift/su_max          0.0320
_refine_ls_shift/su_mean         0.0063
_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          0.0558
_refine_ls_wR_factor_ref         0.0572
_reflns_number_gt                772
_reflns_number_total             1234
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            wf5116sup1.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:

'_diffrn_radiation_probe' value 'X-ray' changed to 'x-ray' according
to /home/saulius/struct/CIF-dictionaries/IUCr/cif_core.dic dictionary
named 'cif_core.dic' version 2.4.5 from 2014-11-21.

Automatic conversion script
Id: cif_fix_values 3866 2015-08-17 15:13:47Z robertas 
;
_cod_original_cell_volume        168.7522
_cod_database_code               2310785