Binary Boron-Rich Borides of Magnesium: Single-Crystal Investigations and Properties of MgB7 and the New Boride Mg~5B44
Alexis Pediaditakis; Melanie Schroeder; Vanessa Sagawe; Thilo Ludwig; Harald Hillebrecht; Inorganic Chemistry 49 (2010) 10882–10893; doi:10.1021/ic1012389

data_4317141
_publ_contact_author_address
;
 Albert-Ludwigs-Universit\"at Freiburg
 Institut f\"ur Anorganische und Analytische Chemie
 Albertstr. 21
 D-79104 Freiburg
 Germany
;
_publ_contact_author_email       harald.hillebrecht@ac.uni-freiburg.de
_publ_contact_author_fax         +49-(0)761-203-6012
_publ_contact_author_name        'Prof. Dr. Harald Hillebrecht'
_publ_contact_author_phone       +49-(0)761-203-6131
_publ_section_title
;
 Binary Boron-Rich Borides of Magnesium: Single-Crystal Investigations and
 Properties of MgB7 and the New Boride Mg~5B44
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              10882
_journal_page_last               10893
_journal_paper_doi               10.1021/ic1012389
_journal_volume                  49
_journal_year                    2010
_chemical_formula_sum            'B7 Mg'
_chemical_formula_weight         99.98
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           74
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-I 2b 2'
_symmetry_space_group_name_H-M   'I m m a'
_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            8
_cell_length_a                   10.4782(16)
_cell_length_b                   5.9769(9)
_cell_length_c                   8.1245(19)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      35
_cell_measurement_theta_min      20
_cell_volume                     508.81(16)
_computing_cell_refinement       Software_Nonius_CAD4
_computing_data_reduction        CAD46(Dr.E.Keller,Univ.Freiburg)
_computing_molecular_graphics    'Diamond (Crystal impact, 2005)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  Nonius_CAD4
_diffrn_measurement_method       omega-2theta-scan
_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  0.0293
_diffrn_reflns_av_sigmaI/netI    0.0221
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            10498
_diffrn_reflns_theta_full        74.85
_diffrn_reflns_theta_max         74.85
_diffrn_reflns_theta_min         5.75
_diffrn_standards_decay_%        0
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.332
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            dark_red_transparent
_exptl_crystal_density_diffrn    2.610
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       flat_elongated_rod
_exptl_crystal_F_000             376
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.635
_refine_diff_density_min         -0.387
_refine_diff_density_rms         0.077
_refine_ls_extinction_coef       0.019(3)
_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   1.011
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     46
_refine_ls_number_reflns         2842
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.011
_refine_ls_R_factor_all          0.0343
_refine_ls_R_factor_gt           0.0178
_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^)+(0.0211P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0388
_refine_ls_wR_factor_ref         0.0423
_reflns_number_gt                2193
_reflns_number_total             2842
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic1012389_si_002_2.cif
_cod_data_source_block           mgb7
_cod_database_code               4317141