High-pressure syntheses of α-RE~2~B~4~O~9~ (RE = Sm, Ho), with a structure type displaying edge-sharing BO~4~ tetrahedra
Emme, Holger; Huppertz, Hubert; Acta Crystallographica Section C 61 (2005) i29–i31; doi:10.1107/S0108270104030446

data_2014708
_publ_section_title
;
 High-pressure syntheses of \a-RE~2~B~4~O~9~ (RE = Sm, Ho), with a
 structure type displaying edge-sharing BO~4~ tetrahedra
;
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i29
_journal_page_last               i31
_journal_paper_doi               10.1107/S0108270104030446
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'Ho2 B4 O9'
_chemical_formula_moiety         'Ho2 B4 O9'
_chemical_formula_sum            'B4 Ho2 O9'
_chemical_formula_weight         517.10
_chemical_name_common            '\a-Diholmium tetraborate'
_chemical_name_systematic
;
Diholmium tetraborate
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 99.83(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            20
_cell_length_a                   25.090(5)
_cell_length_b                   4.3941(9)
_cell_length_c                   24.742(5)
_cell_measurement_reflns_used    8000
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.3
_cell_measurement_theta_min      3.3
_cell_volume                     2687.7(10)
_computing_cell_refinement       'Please provide missing details'
_computing_data_collection       'Please provide missing details'
_computing_data_reduction        'Please provide missing details'
_computing_molecular_graphics    'DIAMOND (Brandenburg & Berndt, 1999)'
_computing_publication_material  'enCIFer (Allen et al., 2004) and SHELXL97'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'STOE IPDS'
_diffrn_measurement_method       'profile data from \f 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  0.0683
_diffrn_reflns_av_sigmaI/netI    0.0488
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -30
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            8632
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         3.30
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    29.258
_exptl_absorpt_correction_T_max  0.0503
_exptl_absorpt_correction_T_min  0.0089
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   '(HABITUS; Herrendorf, 1993-1997)'
_exptl_crystal_colour            light-yellow
_exptl_crystal_density_diffrn    6.389
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             4520
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.1
_refine_diff_density_max         2.260
_refine_diff_density_min         -2.502
_refine_ls_extinction_coef       0.00023(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     340
_refine_ls_number_reflns         2507
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_R_factor_all          0.0381
_refine_ls_R_factor_gt           0.0328
_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^)+(0.0486P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0757
_refine_ls_wR_factor_ref         0.0772
_reflns_number_gt                2169
_reflns_number_total             2507
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            iz1049.cif
_cod_data_source_block           II
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_original_formula_sum        'Ho2 B4 O9'
_cod_database_code               2014708
_cod_database_fobs_code          2014708