Tuning birefringence in alkaline-earth metal oxyhalides through diverse mixed-cation coordination architectures.
Zeng, Shenghong; Maimaiti, Mayinuer; Wu, Jinche; Han, Tingwen; Chai, Hui; Zhang, Fangfang; Zhang, Min; Dalton transactions (Cambridge, England : 2003) 55 (2026) 611–619; doi:10.1039/d5dt02624e

data_7720507
_publ_section_title
;
 Tuning birefringence in alkaline-earth metal oxyhalides through diverse
 mixed-cation coordination architectures.
;
_journal_issue                   2
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              611
_journal_page_last               619
_journal_paper_doi               10.1039/d5dt02624e
_journal_volume                  55
_journal_year                    2026
_chemical_formula_moiety         'Ba5 Br10 O4 Pb4'
_chemical_formula_sum            'Ba5 Br10 O4 Pb4'
_chemical_formula_weight         2378.56
_space_group_crystal_system      tetragonal
_space_group_IT_number           85
_space_group_name_Hall           '-P 4a'
_space_group_name_H-M_alt        'P 4/n :2'
_atom_sites_solution_primary     direct
_audit_creation_date             2025-02-17
_audit_creation_method
;
Olex2 1.5-alpha
(compiled 2025.02.13 svn.rdd3e1f77 for OlexSys, GUI svn.r7147)
;
_audit_update_record
;
2025-10-19 deposited with the CCDC.	2025-12-02 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   12.8099(16)
_cell_length_b                   12.8099(16)
_cell_length_c                   8.3153(15)
_cell_measurement_reflns_used    7777
_cell_measurement_temperature    293.00
_cell_measurement_theta_max      27.52
_cell_measurement_theta_min      2.25
_cell_volume                     1364.5(3)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5-alpha (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-alpha (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL  (Sheldrick, 2008)'
_computing_structure_solution    'XS  (Sheldrick, 2008)'
_diffrn_ambient_temperature      298
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0535
_diffrn_reflns_av_unetI/netI     0.0346
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            9629
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.517
_diffrn_reflns_theta_min         2.248
_diffrn_source_current           1.4
_diffrn_source_power             0.07
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    46.315
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.3287
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1646 before and 0.0921 after correction.
The Ratio of minimum to maximum transmission is 0.4409.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    5.789
_exptl_crystal_description       plate
_exptl_crystal_F_000             1980
_refine_diff_density_max         1.356
_refine_diff_density_min         -1.421
_refine_diff_density_rms         0.338
_refine_ls_extinction_coef       0.00099(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2018/3 (Sheldrick 2018)'
_refine_ls_goodness_of_fit_ref   1.258
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     55
_refine_ls_number_reflns         1571
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.258
_refine_ls_R_factor_all          0.0250
_refine_ls_R_factor_gt           0.0235
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+7.7143P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0513
_refine_ls_wR_factor_ref         0.0527
_reflns_Friedel_coverage         0.000
_reflns_number_gt                1506
_reflns_number_total             1571
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5dt02624e2.cif
_cod_data_source_block           p86-3-long
_cod_original_cell_volume        1364.5(4)
_cod_original_sg_symbol_H-M      'P 4/n'
_cod_database_code               7720507
_shelx_shelxl_version_number     2018/3
_olex2_refinement_description
;
;
_shelx_res_checksum              23445
_olex2_submission_special_instructions 'No special instructions were received'