Crystal structures of potassium terbium(III) tetrasulfidogermanate, KTbGeS~4~, and potassium praseodymium(III) tetraselenidogermanat, KPrGeSe~4~
B. C. Chan; P. K. Dorhout; Zeitschrift für Kristallographie - New Crystal Structures 220 (2005) 7–8; doi:

data_8102888
_publ_section_title
;
Crystal structures of potassium terbium(III) tetrasulfidogermanate, 
KTbGeS~4~, and potassium praseodymium(III) tetraselenidogermanat, 
KPrGeSe~4~
;
_journal_issue                   1
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              7
_journal_page_last               8
_journal_volume                  220
_journal_year                    2005
_chemical_formula_sum            'Ge K Pr Se4'
_chemical_formula_weight         568.44
_chemical_name_systematic
'potassium praseodymium(III) tetraselenidogermanate'
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 108.157(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.8280(8)
_cell_length_b                   7.0105(8)
_cell_length_c                   8.9868(10)
_cell_measurement_temperature    298(2)
_cell_volume                     408.76(8)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_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      298(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0430
_diffrn_reflns_av_sigmaI/netI    0.0551
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            2578
_diffrn_reflns_theta_full        23.29
_diffrn_reflns_theta_max         23.29
_diffrn_reflns_theta_min         2.39
_exptl_absorpt_coefficient_mu    27.777
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.430994
_exptl_absorpt_correction_type   SADABS
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    4.618
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             492
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.01
_refine_diff_density_max         1.721
_refine_diff_density_min         -1.167
_refine_diff_density_rms         0.387
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.45(5)
_refine_ls_extinction_coef       0.0280(16)
_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   1.110
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     66
_refine_ls_number_reflns         1178
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.110
_refine_ls_R_factor_all          0.0381
_refine_ls_R_factor_gt           0.0371
_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^)+(0.0510P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0893
_refine_ls_wR_factor_ref         0.0898
_reflns_number_gt                1153
_reflns_number_total             1178
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            409812.cff
_cod_data_source_block           pdcd236
_cod_original_sg_symbol_H-M      P2(1)
_cod_original_formula_sum        'Ge1 K1 Pr1 Se4'
_cod_database_code               8102888