Two-dimensional Lead-Free Double Perovskite Ferroelastic with Dynamic Thermochromism
Su, Chang-Yuan; Yi, Heng-Guan; Ni, Hao-Fei; Du, Guowei; Xia, San-Qiang; Liu, Zunqi; Zhang, Zhi-Xu; Fu, Da-Wei; Chemical Science  (2025) –; doi:10.1039/D5SC05158D

data_1576182
_publ_section_title
;
 Two-dimensional Lead-Free Double Perovskite Ferroelastic with Dynamic
 Thermochromism
;
_journal_name_full               'Chemical Science'
_journal_paper_doi               10.1039/D5SC05158D
_journal_year                    2025
_chemical_formula_sum            'C20 Ag Bi Br8 N4'
_chemical_formula_weight         1252.37
_space_group_crystal_system      tetragonal
_space_group_IT_number           139
_space_group_name_Hall           '-I 4 2'
_space_group_name_H-M_alt        'I 4/m m m'
_audit_creation_method           SHELXL-2018/3
_audit_update_record
;
2023-06-20 deposited with the CCDC.	2025-10-27 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            1
_cell_length_a                   5.818(2)
_cell_length_b                   5.818(2)
_cell_length_c                   28.386(15)
_cell_measurement_reflns_used    2769
_cell_measurement_temperature    347(2)
_cell_measurement_theta_max      28.62
_cell_measurement_theta_min      2.47
_cell_volume                     960.8(7)
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      347(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.998
_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  0.1427
_diffrn_reflns_av_unetI/netI     0.1150
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            11483
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.493
_diffrn_reflns_theta_min         2.870
_exptl_absorpt_coefficient_mu    13.412
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    2.164
_exptl_crystal_description       block
_exptl_crystal_F_000             558
_refine_diff_density_max         1.225
_refine_diff_density_min         -1.469
_refine_diff_density_rms         0.162
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.050
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     30
_refine_ls_number_reflns         498
_refine_ls_number_restraints     119
_refine_ls_restrained_S_all      1.232
_refine_ls_R_factor_all          0.0985
_refine_ls_R_factor_gt           0.0609
_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^)+(0.0638P)^2^+6.2733P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1504
_refine_ls_wR_factor_ref         0.1827
_reflns_Friedel_coverage         0.000
_reflns_number_gt                315
_reflns_number_total             498
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc05158d4.cif
_cod_data_source_block           mo_scy_616_1s_347k_2_0m_b_pl
_cod_original_cell_volume        960.8(8)
_cod_database_code               1576182
_shelx_shelxl_version_number     2018/3
_shelx_res_checksum              83378