The structure of kaliophilite KAlSiO~4~, a long-lasting crystallographic problem
Mugnaioli, Enrico; Bonaccorsi, Elena; Lanza, Arianna E.; Elkaim, Erik; Diez-Gómez, Virginia; Sobrados, Isabel; Gemmi, Mauro; Gregorkiewitz, Miguel; IUCrJ 7 (2020) –; doi:10.1107/S2052252520012270

data_1559218
_publ_section_title
;
 The structure of kaliophilite KAlSiO~4~, a long-lasting crystallographic
 problem
;
_journal_coeditor_code           FC5047SUP1
_journal_issue                   6
_journal_name_full               IUCrJ
_journal_page_first
;
;
_journal_paper_doi               10.1107/S2052252520012270
_journal_volume                  7
_journal_year                    2020
_chemical_formula_moiety         'Al27 O108 Si27, 24.668(K), 2.332(Na)'
_chemical_formula_sum            'Al27 K24.67 Na2.33 O108 Si27'
_chemical_formula_weight         4233.03
_chemical_name_common            kaliophilite
_space_group_crystal_system      trigonal
_space_group_IT_number           143
_space_group_name_Hall           'P 3'
_space_group_name_H-M_alt        'P 3'
_audit_creation_method           SHELXL-2018/1
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            2
_cell_length_a                   27.0597(16)
_cell_length_b                   27.0597(16)
_cell_length_c                   8.5587(6)
_cell_measurement_reflns_used    127892
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      37.623
_cell_measurement_theta_min      0.869
_cell_volume                     5427.3(6)
_computing_structure_refinement  'SHELXL-2018/1 (Sheldrick, 2018)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type
'Bruker Smart Breeze diffractometer equipped with an air-cooled CCD detector'
_diffrn_measurement_method
'profile data from theta/2theta (\q/2\q) scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0613
_diffrn_reflns_av_unetI/netI     0.0646
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -46
_diffrn_reflns_limit_k_max       46
_diffrn_reflns_limit_k_min       -39
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            127892
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         37.623
_diffrn_reflns_theta_min         0.869
_diffrn_source                   'conventional X-ray tube'
_exptl_absorpt_coefficient_mu    1.630
_exptl_absorpt_correction_T_max  0.7474
_exptl_absorpt_correction_T_min  0.5228
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            'translucent white'
_exptl_crystal_density_diffrn    2.590
_exptl_crystal_density_method    none
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             4174.7
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         2.295
_refine_diff_density_min         -1.425
_refine_diff_density_rms         0.261
_refine_ls_abs_structure_details
;
 Twinning involves inversion, so Flack parameter cannot be determined
;
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.021
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     589
_refine_ls_number_reflns         37707
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.021
_refine_ls_R_factor_all          0.0898
_refine_ls_R_factor_gt           0.0768
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0519P)^2^+59.5879P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1733
_refine_ls_wR_factor_ref         0.1822
_reflns_Friedel_coverage         0.995
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.989
_reflns_number_gt                33165
_reflns_number_total             37707
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            fc5047.cif
_cod_data_source_block           I
_cod_original_cell_volume        5427.3(7)
_cod_database_code               1559218
_shelx_shelxl_version_number     2018/1
_shelx_res_checksum              16192
_shelx_hkl_checksum              69098