Double second-order Jahn-Teller strategy driven NLO response in sulfate crystal Nb<sub>2</sub>O<sub>2</sub>(TeO<sub>3</sub>)<sub>2</sub>(SO<sub>4</sub>) with a large birefringence.
Xu, Jingsha; Zhang, Xiaofeng; Chen, Shanshan; Wang, Weiyi; Qiu, Wenbo; Cai, Weizhao; Zhou, Liujiang; Dalton transactions (Cambridge, England : 2003) 55 (2026) 5189–5196; doi:10.1039/d5dt03078a

data_7720607
_publ_section_title
;
 Double second-order Jahn-Teller strategy driven NLO response in sulfate
 crystal
 Nb<sub>2</sub>O<sub>2</sub>(TeO<sub>3</sub>)<sub>2</sub>(SO<sub>4</sub>)
 with a large birefringence.
;
_journal_issue                   13
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              5189
_journal_page_last               5196
_journal_paper_doi               10.1039/d5dt03078a
_journal_volume                  55
_journal_year                    2026
_chemical_formula_moiety         'Nb2 O12 S Te2'
_chemical_formula_sum            'Nb2 O12 S Te2'
_chemical_formula_weight         665.08
_space_group_crystal_system      monoclinic
_space_group_IT_number           9
_space_group_name_Hall           'C -2yc'
_space_group_name_H-M_alt        'C 1 c 1'
_atom_sites_solution_primary     iterative
_audit_creation_date             2026-02-25
_audit_creation_method
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_audit_update_record
;
2026-03-01 deposited with the CCDC.	2026-03-06 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 107.220(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   20.0326(7)
_cell_length_b                   6.5977(3)
_cell_length_c                   7.6438(2)
_cell_measurement_reflns_used    3399
_cell_measurement_temperature    296.00
_cell_measurement_theta_max      31.471
_cell_measurement_theta_min      4.087
_cell_volume                     964.99(6)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_collection       'APEX5 (Bruker AXS Inc.; v2023.9-2)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'olex2.solve 1.5 (Bourhis et al., 2015)'
_diffrn_ambient_temperature      296.00
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_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  0.0491
_diffrn_reflns_av_unetI/netI     0.0367
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       -28
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            14713
_diffrn_reflns_point_group_measured_fraction_full 0.975
_diffrn_reflns_point_group_measured_fraction_max 0.955
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.504
_diffrn_reflns_theta_min         2.129
_diffrn_source_current           1.4
_diffrn_source_power             0.07
_diffrn_source_voltage           50.0
_exptl_absorpt_coefficient_mu    8.581
_exptl_absorpt_correction_T_max  0.0470
_exptl_absorpt_correction_T_min  0.0159
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.0697 before and 0.0635 after correction.
The Ratio of minimum to maximum transmission is 0.3383.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    4.578
_exptl_crystal_description       plate
_exptl_crystal_F_000             1192
_exptl_crystal_size_max          0.024
_exptl_crystal_size_mid          0.024
_exptl_crystal_size_min          0.001
_refine_diff_density_max         1.023
_refine_diff_density_min         -0.674
_refine_diff_density_rms         0.195
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.14(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     165
_refine_ls_number_reflns         2812
_refine_ls_number_restraints     20
_refine_ls_restrained_S_all      1.007
_refine_ls_R_factor_all          0.0359
_refine_ls_R_factor_gt           0.0288
_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^)+(0.0317P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0629
_refine_ls_wR_factor_ref         0.0662
_reflns_Friedel_coverage         0.908
_reflns_Friedel_fraction_full    0.949
_reflns_Friedel_fraction_max     0.910
_reflns_number_gt                2403
_reflns_number_total             2812
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5dt03078a2.cif
_cod_data_source_block           t1
_cod_depositor_comments          'Adding full bibliography for 7720607.cif.'
_cod_database_code               7720607
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_max   0.991
_shelx_estimated_absorpt_t_min   0.821
_olex2_refinement_description
;
1. Twinned data refinement
 Scales: 0.86(8)
 0.14(8)
2. Uiso/Uaniso restraints and constraints
Uanis(Nb2A) \\sim Ueq: with sigma of 0.001 and sigma for terminal atoms of 0.002
Uanis(O11) \\sim Ueq: with sigma of 0.005 and sigma for terminal atoms of 0.01
Uanis(O8) \\sim Ueq: with sigma of 0.01 and sigma for terminal atoms of 0.02
3. Others
 Sof(Nb2A)=1-FVAR(1)
 Sof(Nb2)=FVAR(1)
;
_shelx_res_checksum              39314
_shelx_hkl_checksum              20330
_olex2_submission_special_instructions 'No special instructions were received'