Tb~2~Ni~2~Mg~3~: a new structure type derived from the Ru~3~Al~2~B~2~ type
Solokha, Pavlo; De Negri, Serena; Saccone, Adriana; Pavlyuk, Volodymyr; Marciniak, Bernard; Tedenac, Jean-Claude; Acta Crystallographica Section C 63 (2007) i13–i16; doi:10.1107/S0108270107001503

data_2015819
_publ_section_title
;
 Tb~2~Ni~2~Mg~3~: a new structure type derived from the Ru~3~Al~2~B~2~
 type
;
_journal_coeditor_code           SQ3057
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              i13
_journal_page_last               i16
_journal_paper_doi               10.1107/S0108270107001503
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'Tb2 Ni2 Mg3'
_chemical_formula_moiety         '2(Ni Tb), 3(Mg)'
_chemical_formula_sum            'Mg3 Ni2 Tb2'
_chemical_formula_weight         508.19
_chemical_name_common            'Trimagnesium dinickel diterbium'
_chemical_name_systematic
;
diterbium dinickel trimagnesium
;
_space_group_IT_number           65
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-C 2 2'
_symmetry_space_group_name_H-M   'C m m m'
_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            2
_cell_length_a                   3.9788(7)
_cell_length_b                   21.203(4)
_cell_length_c                   3.6583(7)
_cell_measurement_reflns_used    940
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      26.37
_cell_measurement_theta_min      3.84
_cell_volume                     308.62(10)
_computing_cell_refinement       'CrysAlis CCD'
_computing_data_collection       'CrysAlis CCD (Oxford Diffraction, 2004)'
_computing_data_reduction        'CrysAlis RED (Oxford Diffraction, 2005)'
_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      295(2)
_diffrn_detector_area_resol_mean 0
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_device_type  'Oxford Diffraction Xcalibur'
_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  0.0431
_diffrn_reflns_av_sigmaI/netI    0.0224
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       2
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            940
_diffrn_reflns_theta_full        26.37
_diffrn_reflns_theta_max         26.37
_diffrn_reflns_theta_min         3.84
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    28.795
_exptl_absorpt_correction_T_max  0.313
_exptl_absorpt_correction_T_min  0.075
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details   '(CrysAlis RED; Oxford Diffraction, 2005)'
_exptl_crystal_colour            'metallic dark grey'
_exptl_crystal_density_diffrn    5.469
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregularly shaped'
_exptl_crystal_F_000             444
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.04
_refine_diff_density_max         2.233
_refine_diff_density_min         -1.213
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.100
_refine_ls_matrix_type           full
_refine_ls_number_parameters     16
_refine_ls_number_reflns         213
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.100
_refine_ls_R_factor_all          0.0352
_refine_ls_R_factor_gt           0.0323
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0609P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0764
_refine_ls_wR_factor_ref         0.0780
_reflns_number_gt                199
_reflns_number_total             213
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sq3057.cif
_cod_data_source_block           I
_cod_database_code               2015819
_cod_database_fobs_code          2015819