MgIr~3~Si~7~, a new magnesium iridium silicide with the ScRh~3~Si~7~ type structure
Lorenz, Peter; Jung, Walter; Acta Crystallographica Section E 62 (2006) i173–i175; doi:10.1107/S1600536806025323

data_2210014
_publ_section_title
;
 MgIr~3~Si~7~, a new magnesium iridium silicide with the ScRh~3~Si~7~
 type structure
;
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i173
_journal_page_last               i175
_journal_paper_doi               10.1107/S1600536806025323
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'Mg Ir3 Si7'
_chemical_formula_structural     'Mg Ir3 Si7'
_chemical_formula_sum            'Ir3 Mg Si7'
_chemical_formula_weight         797.54
_chemical_name_common            'magnesium triiridium heptasilicide'
_chemical_name_systematic
;
magnesium triiridium heptasilicide
;
_space_group_IT_number           167
_symmetry_cell_setting           trigonal
_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           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            6
_cell_length_a                   7.5232(8)
_cell_length_b                   7.5232(8)
_cell_length_c                   19.959(3)
_cell_measurement_reflns_used    28
_cell_measurement_temperature    294(3)
_cell_measurement_theta_max      48.36
_cell_measurement_theta_min      11.82
_cell_volume                     978.3(2)
_computing_cell_refinement       'Guinier film method (Bach, 1978)'
_computing_data_collection       'X-AREA (Stoe & Cie, 2001)'
_computing_data_reduction        'X-AREA (Stoe & Cie, 2001)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 1999)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      294(3)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Stoe IPDS-I'
_diffrn_measurement_method       \w
_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  0.0478
_diffrn_reflns_av_sigmaI/netI    0.0206
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            2857
_diffrn_reflns_theta_full        28.13
_diffrn_reflns_theta_max         28.13
_diffrn_reflns_theta_min         3.73
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    62.333
_exptl_absorpt_correction_T_max  0.3056
_exptl_absorpt_correction_T_min  0.0959
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
;
[X-RED (Stoe & Cie, 2001), after optimizing the crystal shape
using X-SHAPE (Stoe & Cie, 1999)]
;
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    8.122
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             2046
_exptl_crystal_size_max          0.055
_exptl_crystal_size_mid          0.040
_exptl_crystal_size_min          0.025
_refine_diff_density_max         1.277
_refine_diff_density_min         -1.283
_refine_ls_extinction_coef       0.00157(7)
_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   1.059
_refine_ls_matrix_type           full
_refine_ls_number_parameters     20
_refine_ls_number_reflns         274
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.059
_refine_ls_R_factor_all          0.0218
_refine_ls_R_factor_gt           0.0180
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0238P)^2^+9.1966P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0434
_refine_ls_wR_factor_ref         0.0443
_reflns_number_gt                241
_reflns_number_total             274
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            wm2021.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value 'not measured' was changed to '?' -
the value is undefined or not given.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 

The following automatic conversions were performed:

'_chemical_melting_point' value 'not measured' was changed to '?' -
the value is undefined or not given.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'R -3 c'
_cod_database_code               2210014
_cod_database_fobs_code          2210014