Ba~2~Gd~2~(Si~4~O~13~): a silicate with finite Si~4~O~13~ chains
Wierzbicka-Wieczorek, Maria; Kolitsch, Uwe; Tillmanns, Ekkehart; Acta Crystallographica Section C 66 (2010) i29–i32; doi:10.1107/S0108270110002842

data_2017571
_publ_section_title
;
 Ba~2~Gd~2~(Si~4~O~13~): a silicate with finite Si~4~O~13~ chains
;
_journal_coeditor_code           LG3027
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i29
_journal_page_last               i32
_journal_paper_doi               10.1107/S0108270110002842
_journal_volume                  66
_journal_year                    2010
_chemical_formula_iupac          'Ba2 Gd2 (Si4 O13)'
_chemical_formula_structural     'Ba2 Gd2 (Si4 O13)'
_chemical_formula_sum            'Ba2 Gd2 O13 Si4'
_chemical_formula_weight         909.52
_chemical_name_common            'barium gadolinium silicate'
_chemical_name_systematic
;
dibarium digadolinium(III) tetrasilicate
;
_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_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 104.08(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.896(3)
_cell_length_b                   5.2120(10)
_cell_length_c                   17.549(4)
_cell_measurement_reflns_used    11887
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      35.62
_cell_measurement_theta_min      1.00
_cell_volume                     1144.1(5)
_computing_cell_refinement       'SAINT (Bruker, 2008)'
_computing_data_collection       'APEX2 (Bruker, 2008)'
_computing_data_reduction        'SAINT (Bruker, 2008)'
_computing_molecular_graphics    'ATOMS (Shape Software, 1999)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker APEXII CCD area-detector'
_diffrn_measurement_method       '\f and \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  0.0318
_diffrn_reflns_av_sigmaI/netI    0.0319
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            11887
_diffrn_reflns_theta_full        35.62
_diffrn_reflns_theta_max         35.62
_diffrn_reflns_theta_min         2.39
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    18.727
_exptl_absorpt_correction_T_max  0.7058
_exptl_absorpt_correction_T_min  0.3158
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 2006)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    5.280
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             1600
_exptl_crystal_size_max          0.08
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.02
_refine_diff_density_max         1.298
_refine_diff_density_min         -1.651
_refine_ls_extinction_coef       0.000166(19)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_matrix_type           full
_refine_ls_number_parameters     97
_refine_ls_number_reflns         2625
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.035
_refine_ls_R_factor_all          0.0474
_refine_ls_R_factor_gt           0.0264
_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^)+(0.0150P)^2^+4.2000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0417
_refine_ls_wR_factor_ref         0.0459
_reflns_number_gt                1910
_reflns_number_total             2625
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            lg3027.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2017571
_cod_database_fobs_code          2017571