Redetermination of K~2~Mg~3~(OH)~2~(SO~4~)~3~(H~2~O)~2~ from single-crystal X-ray data revealing the correct hydrogen-atom positions
Weil, Matthias; Acta Crystallographica Section E 77 (2021) 62–65; doi:10.1107/S2056989020016217

data_2243711
_publ_section_title
;
 Redetermination of K~2~Mg~3~(OH)~2~(SO~4~)~3~(H~2~O)~2~ from
 single-crystal X-ray data revealing the correct hydrogen-atom positions
;
_journal_coeditor_code           HB7955
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              62
_journal_page_last               65
_journal_paper_doi               10.1107/S2056989020016217
_journal_volume                  77
_journal_year                    2021
_chemical_formula_iupac          'K2 Mg3 (O H)2 (S O4)3 (H2 O)2'
_chemical_formula_moiety         '4(K +), H12 Mg6 O32 S6 4-'
_chemical_formula_sum            'H6 K2 Mg3 O16 S3'
_chemical_formula_weight         509.36
_chemical_name_systematic
;
Dipotassium trimagnesium dihydroxide tris(sulfate) dihydrate
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           36
_space_group_name_Hall           'C 2c -2'
_space_group_name_H-M_alt        'C m c 21'
_atom_sites_solution_hydrogens   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   17.8228(19)
_cell_length_b                   7.4879(8)
_cell_length_c                   9.7686(10)
_cell_measurement_reflns_used    9959
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      32.990
_cell_measurement_theta_min      2.786
_cell_volume                     1303.7(2)
_computing_cell_refinement
;
SAINT (Bruker, 2015)
;
_computing_data_collection
;
APEX3 (Bruker, 2015)
;
_computing_data_reduction
;
SAINT (Bruker, 2015)
;
_computing_molecular_graphics
;
Atoms for Windows (Dowty, 2006)
;
_computing_publication_material
;
publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
<i>SHELXL2014/7</i> (Sheldrick, 2015)
;
_computing_structure_solution    'coordinates taken from previous refinement'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEXII CCD'
_diffrn_measurement_method       '\w- and \f-scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0420
_diffrn_reflns_av_unetI/netI     0.0196
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            31799
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.060
_diffrn_reflns_theta_min         2.285
_exptl_absorpt_coefficient_mu    1.447
_exptl_absorpt_correction_T_max  0.747
_exptl_absorpt_correction_T_min  0.668
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(<i>SADABS</i>; Krause <i>et al.</i>, 2015)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.595
_exptl_crystal_description       plate
_exptl_crystal_F_000             1024
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.299
_refine_diff_density_min         -0.384
_refine_ls_abs_structure_details
;
Flack <i>x</i> determined using 1125 quotients
[(<i>I</i>^+^)-(<i>I</i>^-^)]/[(<i>I</i>^+^)+(<i>I</i>^-^)]
(Parsons <i>et al.</i>, 2013)
;
_refine_ls_abs_structure_Flack   -0.010(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.072
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     132
_refine_ls_number_reflns         2535
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.072
_refine_ls_R_factor_all          0.0184
_refine_ls_R_factor_gt           0.0165
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0167P)^2^+0.9127P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0387
_refine_ls_wR_factor_ref         0.0393
_reflns_number_gt                2430
_reflns_number_total             2535
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            hb7955sup1.cif
_cod_data_source_block           I
_cod_database_code               2243711
_shelx_hkl_checksum              85023
_shelx_res_checksum              16098
_cod_database_fobs_code 2243711