Calcium Tetraboride ‒ Does It Exist? Synthesis and Properties of a Carbon-Doped Calcium Tetraboride That Is Isotypic with the Known Rare Earth Tetraborides
Schmitt, Ruth; Blaschkowski, Björn; Eichele, Klaus; Meyer, H.-Jürgen; Inorganic Chemistry 45 (2006) 3067–3073; doi:10.1021/ic0518430

data_1101152
_publ_section_title
;
 Calcium Tetraboride -- Does It Exist? Synthesis and Properties of a
 Carbon-Doped Calcium Tetraboride That Is Isotypic with the Known Rare
 Earth Tetraborides
;
_journal_issue                   7
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              3067
_journal_page_last               3073
_journal_paper_doi               10.1021/ic0518430
_journal_volume                  45
_journal_year                    2006
_chemical_formula_sum            'B4 Ca'
_chemical_formula_weight         83.32
_chemical_name_common            'Calcium tetraboride'
_chemical_name_systematic        'Calcium tetraboride'
_space_group_IT_number           127
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-P 4 2ab'
_symmetry_space_group_name_H-M   'P 4/m b m'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.0989(7)
_cell_length_b                   7.0989(7)
_cell_length_c                   4.1353(5)
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      32.71
_cell_measurement_theta_min      4.93
_cell_volume                     208.40(4)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'STOE IPDS'
_diffrn_measurement_method       phi-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  0.0338
_diffrn_reflns_av_sigmaI/netI    0.0142
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            2298
_diffrn_reflns_theta_full        32.71
_diffrn_reflns_theta_max         32.71
_diffrn_reflns_theta_min         4.93
_diffrn_standards_decay_%        0.01
_exptl_absorpt_coefficient_mu    2.527
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    2.656
_exptl_crystal_description       cube
_exptl_crystal_F_000             160
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.5
_exptl_crystal_size_min          0.5
_refine_diff_density_max         0.500
_refine_diff_density_min         -0.345
_refine_diff_density_rms         0.116
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.114
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     22
_refine_ls_number_reflns         240
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.114
_refine_ls_R_factor_all          0.0264
_refine_ls_R_factor_gt           0.0231
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0416P)^2^+0.0341P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0572
_refine_ls_wR_factor_ref         0.0583
_reflns_number_gt                221
_reflns_number_total             240
_reflns_threshold_expression     >2sigma(I)
_cod_database_code               1101152