Noncentrosymmetric rare-earth copper gallium chalcogenides RE3CuGaCh7 (RE=La‒Nd; Ch=S, Se): An unexpected combination
Iyer, Abishek K.; Rudyk, Brent W.; Lin, Xinsong; Singh, Harpreet; Sharma, Arzoo Z.; Wiebe, Christopher R.; Mar, Arthur; Journal of Solid State Chemistry 229 (2015) 150–159; doi:10.1016/j.jssc.2015.05.016

data_1561845
_publ_section_title
;
 Noncentrosymmetric rare-earth copper gallium chalcogenides RE3CuGaCh7
 (RE=La--Nd; Ch=S, Se): An unexpected combination
;
_journal_name_full               'Journal of Solid State Chemistry'
_journal_page_first              150
_journal_page_last               159
_journal_paper_doi               10.1016/j.jssc.2015.05.016
_journal_volume                  229
_journal_year                    2015
_chemical_formula_structural     'La3 Cu Ga Se7'
_chemical_formula_sum            'Cu Ga La3 Se7'
_chemical_formula_weight         1102.71
_chemical_name_common            'lanthanum copper gallium selenide (3/1/1/7)'
_chemical_name_systematic        'lanthanum copper gallium selenide (3/1/1/7)'
_space_group_crystal_system      hexagonal
_space_group_IT_number           173
_space_group_name_Hall           'P 6c'
_space_group_name_H-M_alt        'P 63'
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            2
_cell_length_a                   10.626(10)
_cell_length_b                   10.626(10)
_cell_length_c                   6.392(6)
_cell_measurement_reflns_used    2982
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      26.41
_cell_measurement_theta_min      3.88
_cell_volume                     625.0(10)
_computing_cell_refinement       'Bruker SAINT 8.34A (Bruker, 2013)'
_computing_data_collection       'Bruker APEX 2 (Bruker, 2008)'
_computing_data_reduction        'Bruker SAINT 8.34A'
_computing_molecular_graphics    'ATOMS 5.1 (Dowty, 1999)'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker PLATFORM/SMART APEX II CCD'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0839
_diffrn_reflns_av_unetI/netI     0.0500
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            8781
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.986
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.068
_diffrn_reflns_theta_min         2.213
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    34.160
_exptl_absorpt_correction_T_max  0.4197
_exptl_absorpt_correction_T_min  0.1818
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'Bruker SHELXTL (Sheldrick, 2013)'
_exptl_crystal_colour            grey
_exptl_crystal_density_diffrn    5.859
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       irregular
_exptl_crystal_F_000             938
_exptl_crystal_size_max          0.083
_exptl_crystal_size_mid          0.038
_exptl_crystal_size_min          0.038
_refine_diff_density_max         2.588
_refine_diff_density_min         -1.662
_refine_diff_density_rms         0.389
_refine_ls_abs_structure_details
;
 Flack x determined using 580 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   -0.12(3)
_refine_ls_extinction_coef       0.0029(7)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     41
_refine_ls_number_reflns         1548
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0473
_refine_ls_R_factor_gt           0.0394
_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^)+(0.0490P)^2^+2.3293P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0914
_refine_ls_wR_factor_ref         0.0953
_reflns_Friedel_coverage         0.846
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.979
_reflns_number_gt                1387
_reflns_number_total             1548
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            JSSC-2015-229-150.cif
_cod_data_source_block           La3CuGaSe7
_cod_original_cell_volume        625.0(14)
_cod_database_code               1561845
_shelx_estimated_absorpt_t_min   0.164
_shelx_estimated_absorpt_t_max   0.357
_shelxl_version_number           2013-4
_shelx_res_checksum              6473
_shelx_hkl_checksum              81574