Sr8MgB18O36: a New Alkaline-Earth Borate with a Novel Zero-Dimensional (B18O36)18- Anion Ring
Wenjiao Yao; Xingxing Jiang; Hongwei Huang; Tao Xu; Xiaoshan Wang; Zheshuai Lin; Chuangtian Chen; Inorganic Chemistry 52 (2013) 8291–8293; doi:10.1021/ic401167z

data_4335615
_publ_section_title
;
 Sr8MgB18O36: a New Alkaline-Earth Borate with a Novel Zero-Dimensional
 (B18O36)18- Anion Ring
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              8291
_journal_page_last               8293
_journal_paper_doi               10.1021/ic401167z
_journal_volume                  52
_journal_year                    2013
_chemical_formula_sum            'B18 Mg O36 Sr8'
_chemical_formula_weight         1495.82
_chemical_name_systematic
; 
 magnesium octastrontium octadeca-borate 
;
_space_group_IT_number           167
_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                   11.4271(16)
_cell_length_b                   11.4271(16)
_cell_length_c                   36.913(7)
_cell_measurement_reflns_used    5404
_cell_measurement_temperature    143.1500
_cell_measurement_theta_max      31.4970
_cell_measurement_theta_min      2.1307
_cell_volume                     4174.3(11)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      143.1500
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_method       dtprofit.ref
_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  0.0552
_diffrn_reflns_av_sigmaI/netI    0.0307
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -53
_diffrn_reflns_number            13169
_diffrn_reflns_theta_full        31.50
_diffrn_reflns_theta_max         31.50
_diffrn_reflns_theta_min         2.34
_exptl_absorpt_coefficient_mu    15.388
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.6792
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    3.570
_exptl_crystal_description       chip
_exptl_crystal_F_000             3465
_exptl_crystal_size_max          0.2050
_exptl_crystal_size_mid          0.1900
_exptl_crystal_size_min          0.1500
_refine_diff_density_max         0.801
_refine_diff_density_min         -0.838
_refine_diff_density_rms         0.163
_refine_ls_extinction_coef       0.00091(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   1.293
_refine_ls_matrix_type           full
_refine_ls_number_parameters     98
_refine_ls_number_reflns         1556
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.293
_refine_ls_R_factor_all          0.0363
_refine_ls_R_factor_gt           0.0331
_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^)+(0.0171P)^2^+25.3998P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0618
_refine_ls_wR_factor_ref         0.0627
_reflns_number_gt                1495
_reflns_number_total             1556
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic401167z_si_002.cif
_cod_data_source_block           sm
_cod_original_cell_volume        4174.2(12)
_cod_original_sg_symbol_H-M      'R -3 c'
_cod_original_formula_sum        ' B18 Mg O36 Sr8'
_cod_database_code               4335615