Ternary arsenides ATt3As3 (A=K, Rb; Tt=Ge, Sn) with layered structures
Khatun, Mansura; Stoyko, Stanislav S.; Mar, Arthur; Journal of Solid State Chemistry 238 (2016) 229–235; doi:10.1016/j.jssc.2016.03.035

data_1561509
_publ_section_title
;
 Ternary arsenides ATt3As3 (A=K, Rb; Tt=Ge, Sn) with layered structures
;
_journal_name_full               'Journal of Solid State Chemistry'
_journal_page_first              229
_journal_page_last               235
_journal_paper_doi               10.1016/j.jssc.2016.03.035
_journal_volume                  238
_journal_year                    2016
_chemical_formula_structural     'K Ge3 As3'
_chemical_formula_sum            'As3 Ge3 K'
_chemical_formula_weight         481.63
_chemical_name_common            'potassium germanium arsenide (1/3/3)'
_chemical_name_systematic        'potassium germanium arsenide (1/3/3)'
_space_group_crystal_system      orthorhombic
_space_group_IT_number           62
_space_group_name_Hall           '-P 2ac 2n'
_space_group_name_H-M_alt        'P n m a'
_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                90
_cell_formula_units_Z            4
_cell_length_a                   9.9931(11)
_cell_length_b                   3.7664(4)
_cell_length_c                   18.607(2)
_cell_measurement_reflns_used    2151
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      27.03
_cell_measurement_theta_min      2.19
_cell_volume                     700.33(13)
_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  'SHELXL-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      193(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker PLATFORM/SMART APEX II CCD'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0780
_diffrn_reflns_av_unetI/netI     0.0428
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            9750
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.047
_diffrn_reflns_theta_min         2.189
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    27.330
_exptl_absorpt_correction_T_max  0.5963
_exptl_absorpt_correction_T_min  0.1217
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'Bruker SHELXTL (Sheldrick, 2013)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    4.568
_exptl_crystal_description       needle
_exptl_crystal_F_000             856
_exptl_crystal_size_max          0.288
_exptl_crystal_size_mid          0.027
_exptl_crystal_size_min          0.024
_refine_diff_density_max         1.955
_refine_diff_density_min         -2.330
_refine_diff_density_rms         0.342
_refine_ls_extinction_coef       0.0012(2)
_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   1.084
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     44
_refine_ls_number_reflns         1497
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.084
_refine_ls_R_factor_all          0.0626
_refine_ls_R_factor_gt           0.0386
_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^)+(0.0360P)^2^+6.8843P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0879
_refine_ls_wR_factor_ref         0.0961
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                1092
_reflns_number_total             1497
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            mmc8.cif
_cod_data_source_block           KGe3As3unsplit
_cod_original_cell_volume        700.34(13)
_cod_database_code               1561509
_shelx_estimated_absorpt_t_min   0.047
_shelx_estimated_absorpt_t_max   0.560
_shelxl_version_number           2013-4
_shelx_res_checksum              9091
_shelx_hkl_checksum              57933