Ca~10~(Cr^V^O~4~)~6~(Cr^VI^O~4~), a disordered mixed-valence chromium compound exhibiting inversion twinning
Gyepesová, Dalma; Langer, Vratislav; Acta Crystallographica Section C 69 (2013) 111–113; doi:10.1107/S0108270113000723

data_2018770
_publ_section_title
;
 Ca~10~(Cr^V^O~4~)~6~(Cr^VI^O~4~), a disordered mixed-valence chromium
 compound exhibiting inversion twinning
;
_journal_coeditor_code           BI3051
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              111
_journal_page_last               113
_journal_paper_doi               10.1107/S0108270113000723
_journal_volume                  69
_journal_year                    2013
_chemical_formula_iupac          'Ca10 (Cr O4)6 (Cr O4)'
_chemical_formula_moiety         '7(Cr O4), 10(Ca)'
_chemical_formula_sum            'Ca10 Cr7 O28'
_chemical_formula_weight         1212.80
_chemical_name_systematic
;
decacalcium hexakis[chromate(V)] chromate(VI)
;
_space_group_IT_number           161
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'R 3 -2"c'
_symmetry_space_group_name_H-M   'R 3 c :H'
_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                120.00
_cell_formula_units_Z            6
_cell_length_a                   10.75800(10)
_cell_length_b                   10.75800(10)
_cell_length_c                   38.0730(3)
_cell_measurement_reflns_used    8192
_cell_measurement_temperature    183(2)
_cell_measurement_theta_max      28.32
_cell_measurement_theta_min      2.43
_cell_volume                     3816.02(6)
_computing_cell_refinement       'SAINT (Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 2003)'
_computing_data_reduction
'SAINT (Bruker, 2003) and SADABS (Sheldrick, 2003)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 2012)'
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXTL (Sheldrick, 2008)'
_computing_structure_solution    'SHELXTL (Sheldrick, 2008)'
_diffrn_ambient_temperature      183(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.972
_diffrn_measurement_device_type  'Siemens SMART CCD area-detector'
_diffrn_measurement_method       '\w 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  0.0364
_diffrn_reflns_av_sigmaI/netI    0.0237
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       49
_diffrn_reflns_limit_l_min       -48
_diffrn_reflns_number            13345
_diffrn_reflns_theta_full        28.00
_diffrn_reflns_theta_max         28.32
_diffrn_reflns_theta_min         2.43
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    5.011
_exptl_absorpt_correction_T_max  0.6900
_exptl_absorpt_correction_T_min  0.6612
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2003)'
_exptl_crystal_colour            dark-green
_exptl_crystal_density_diffrn    3.166
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       pyramid
_exptl_crystal_F_000             3552
_exptl_crystal_size_max          0.09
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.470
_refine_diff_density_min         -0.655
_refine_ls_abs_structure_details 'Flack (1983), 995 Friedel pairs'
_refine_ls_abs_structure_Flack   0.53(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.044
_refine_ls_matrix_type           full
_refine_ls_number_parameters     144
_refine_ls_number_reflns         2034
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0269
_refine_ls_R_factor_gt           0.0239
_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^)+(0.0367P)^2^+8.2518P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0585
_refine_ls_wR_factor_ref         0.0602
_reflns_number_gt                1918
_reflns_number_total             2034
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bi3051.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'R 3 c'
_cod_database_code               2018770
_cod_database_fobs_code          2018770