The tetragermanates <i>A</i>~2~Ge~4~O~9~ (<i>A</i> = Na, K and Rb)
Redhammer, Günther J.; Tippelt, Gerold; Acta Crystallographica Section C 69 (2013) 995–1001; doi:10.1107/S0108270113020921

data_2019133
_publ_section_title
;
 The tetragermanates <i>A</i>~2~Ge~4~O~9~ (<i>A</i> = Na, K and Rb)
;
_journal_coeditor_code           FN3142
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              995
_journal_page_last               1001
_journal_paper_doi               10.1107/S0108270113020921
_journal_volume                  69
_journal_year                    2013
_chemical_formula_analytical     'K2 Ge4 O9'
_chemical_formula_iupac          'K2 Ge4 O9'
_chemical_formula_moiety         'Ge4 O9, 2(K)'
_chemical_formula_sum            'Ge4 K2 O9'
_chemical_formula_weight         512.56
_chemical_name_common            'potassium tetragermanate'
_chemical_name_systematic
;
Dipotassium tetragermanate
;
_space_group_crystal_system      trigonal
_space_group_IT_number           165
_space_group_name_Hall           '-P 3 2"c'
_space_group_name_H-M_alt        'P -3 c 1'
_symmetry_space_group_name_Hall  '-P 3 2"c'
_symmetry_space_group_name_H-M   'P -3 c 1'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            6
_cell_length_a                   11.8461(4)
_cell_length_b                   11.8461(4)
_cell_length_c                   9.8009(4)
_cell_measurement_reflns_used    12842
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      28.91
_cell_measurement_theta_min      1.99
_cell_volume                     1191.10(7)
_computing_cell_refinement       'APEX2 (Bruker, 2007)'
_computing_data_collection       'APEX2 (Bruker, 2007)'
_computing_data_reduction        'APEX2 (Bruker, 2007)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 1999)'
_computing_publication_material  'WinGX (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      295(2)
_diffrn_measured_fraction_theta_full 0.973
_diffrn_measured_fraction_theta_max 0.973
_diffrn_measurement_device_type  'Bruker SMART APEX'
_diffrn_measurement_method       '\w scan at four different \f positions'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0255
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            12842
_diffrn_reflns_theta_full        28.91
_diffrn_reflns_theta_max         28.91
_diffrn_reflns_theta_min         1.99
_exptl_absorpt_coefficient_mu    16.076
_exptl_absorpt_correction_T_max  0.748
_exptl_absorpt_correction_T_min  0.441
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
;
[multiscan absorption correction using APEX2 (Bruker, 2007)]
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    4.287
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1428
_exptl_crystal_size_max          0.17
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.385
_refine_diff_density_min         -0.579
_refine_ls_extinction_coef       0.00549(16)
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.144
_refine_ls_matrix_type           full
_refine_ls_number_parameters     71
_refine_ls_number_reflns         1026
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.144
_refine_ls_R_factor_all          0.0153
_refine_ls_R_factor_gt           0.0143
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0151P)^2^+1.1161P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.0345
_reflns_number_gt                984
_reflns_number_total             1026
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            fn3142.cif
_cod_data_source_block           K2Ge4O9
_cod_database_code               2019133
_cod_database_fobs_code          2019133