Ba<i>Ln</i>~2~Se~4~ (<i>Ln</i> = Er, Tm and Yb)
Bugaris, Daniel E.; Ibers, James A.; Acta Crystallographica Section C 65 (2009) i60–i62; doi:10.1107/S0108270109030571

data_2017318
_publ_section_title
;
 Ba<i>Ln</i>~2~Se~4~ (<i>Ln</i> = Er, Tm and Yb)
;
_journal_coeditor_code           SQ3208
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i60
_journal_page_last               i62
_journal_paper_doi               10.1107/S0108270109030571
_journal_volume                  65
_journal_year                    2009
_chemical_formula_iupac          'Ba Yb2 Se4'
_chemical_formula_moiety         '2(Se2 Yb), Ba'
_chemical_formula_sum            'Ba Se4 Yb2'
_chemical_formula_weight         799.26
_chemical_name_systematic
;
Barium diytterbium tetraselenide
;
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.580(3)
_cell_length_b                   4.1150(8)
_cell_length_c                   14.860(3)
_cell_measurement_reflns_used    3836
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.13
_cell_measurement_theta_min      2.74
_cell_volume                     769.3(3)
_computing_cell_refinement       'APEX2 (Bruker, 2006)'
_computing_data_collection       'APEX2 (Bruker, 2006)'
_computing_data_reduction        'SAINT (Bruker, 2006)'
_computing_molecular_graphics    'CrystalMaker (Palmer, 2008)'
_computing_publication_material  'SHELXTL or SHELXL97 (Sheldrick, 2008a)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008a)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008a)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.937
_diffrn_measurement_device_type  'Bruker APEXII'
_diffrn_measurement_method       \w
_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  0.0335
_diffrn_reflns_av_sigmaI/netI    0.0194
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            8818
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.68
_diffrn_reflns_theta_min         2.12
_exptl_absorpt_coefficient_mu    47.991
_exptl_absorpt_correction_T_max  0.4291
_exptl_absorpt_correction_T_min  0.1132
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
;
face indexed (SADABS; Sheldrick, 2008b)
;
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    6.901
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1328
_exptl_crystal_size_max          0.172
_exptl_crystal_size_mid          0.021
_exptl_crystal_size_min          0.021
_refine_diff_density_max         1.346
_refine_diff_density_min         -1.895
_refine_ls_extinction_coef       0.00203(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008a)'
_refine_ls_goodness_of_fit_ref   1.219
_refine_ls_matrix_type           full
_refine_ls_number_parameters     44
_refine_ls_number_reflns         1056
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.219
_refine_ls_R_factor_all          0.0204
_refine_ls_R_factor_gt           0.0182
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     'calc w=1/[\s^2^(Fo^2^)+(0.02Fo^2^)^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0411
_refine_ls_wR_factor_ref         0.0416
_reflns_number_gt                1012
_reflns_number_total             1056
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            sq3208.cif
_cod_data_source_block           III
_cod_original_cell_volume        769.2(3)
_cod_database_code               2017318
_cod_database_fobs_code          2017318