Centrosymmetric to noncentrosymmetric structural transformation of new quaternary selenides induced by isolated dimeric [Sn2Se4] units: from Ba8Ga2Sn7Se18 to Ba10Ga2Sn9Se22
Li, Yan-Yan; Wang, Jin-Qiu; Liu, Peng-Fei; Lin, Hua; Chen, Ling; Wu, Li-Ming; RSC Adv. 7 (2017) 8082–; doi:10.1039/C6RA27253C

data_7227499
_publ_section_title
;
 Centrosymmetric to noncentrosymmetric structural transformation of new
 quaternary selenides induced by isolated dimeric [Sn2Se4] units: from
 Ba8Ga2Sn7Se18 to Ba10Ga2Sn9Se22
;
_journal_issue                   14
_journal_name_full               'RSC Adv.'
_journal_page_first              8082
_journal_paper_doi               10.1039/C6RA27253C
_journal_volume                  7
_journal_year                    2017
_chemical_formula_sum            'Ba8 Ga2 Se18 Sn7'
_chemical_formula_weight         3490.27
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           62
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2n'
_symmetry_space_group_name_H-M   'P n m a'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2017-01-13 deposited with the CCDC.
2017-01-18 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   12.466(9)
_cell_length_b                   9.358(6)
_cell_length_c                   18.136(13)
_cell_measurement_reflns_used    4812
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.5205
_cell_measurement_theta_min      2.2460
_cell_volume                     2116(3)
_computing_cell_refinement       'Bruker XSCANS'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 27.50
_diffrn_measured_fraction_theta_max 27.50
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0606
_diffrn_reflns_av_sigmaI/netI    0.0352
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            15597
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         2.25
_exptl_absorpt_coefficient_mu    28.089
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.7097
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    5.479
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2944
_exptl_crystal_size_max          0.2000
_exptl_crystal_size_mid          0.2000
_exptl_crystal_size_min          0.2000
_refine_diff_density_max         2.191
_refine_diff_density_min         -1.773
_refine_diff_density_rms         0.367
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.137
_refine_ls_matrix_type           full
_refine_ls_number_parameters     99
_refine_ls_number_reflns         2488
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.137
_refine_ls_R_factor_all          0.0490
_refine_ls_R_factor_gt           0.0415
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0437P)^2^+8.5302P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0920
_refine_ls_wR_factor_ref         0.0959
_reflns_number_gt                2207
_reflns_number_total             2488
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c6ra27253c2.cif
_cod_data_source_block           1-Ba8Ga2Sn7Se18
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

'_exptl_absorpt_correction_type' value 'Multi-scan' changed to
'multi-scan' according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 4268 2015-11-12 08:31:59Z antanas 
;
_cod_original_sg_symbol_H-M      Pnma
_cod_database_code               7227499