Spin Glass Behavior of Isolated, Geometrically Frustrated Tetrahedra of Iron Atoms in the Intermetallic La21Fe8Sn7C12
Evan M. Benbow; Naresh S. Dalal; Susan E. Latturner; Journal of the American Chemical Society 131 (2009) 3349–3354; doi:10.1021/ja809084n

data_4104279
_publ_contact_author_address
;
 Department of Chemistry and Biochemistry
 Florida State University
 Tallahassee, FL  32308
;
_publ_contact_author_email       latturne@chem.fsu.edu
_publ_contact_author_fax         8506448281
_publ_contact_author_name        'Prof. Susan E. Latturner'
_publ_contact_author_phone       8506444047
_publ_section_title
;
 Spin Glass Behavior of Isolated, Geometrically Frustrated Tetrahedra of
 Iron Atoms in the Intermetallic La21Fe8Sn7C12
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              3349
_journal_page_last               3354
_journal_paper_doi               10.1021/ja809084n
_journal_volume                  131
_journal_year                    2009
_chemical_formula_sum            'C12 Al2.06 Fe8 Ge4.94 La21'
_chemical_formula_weight         3922.20
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           225
_symmetry_cell_setting           cubic
_symmetry_space_group_name_Hall  '-F 4 2 3'
_symmetry_space_group_name_H-M   'F m -3 m'
_atom_sites_solution_hydrogens   none
_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            4
_cell_length_a                   16.1589(4)
_cell_length_b                   16.1589(4)
_cell_length_c                   16.1589(4)
_cell_measurement_reflns_used    14562
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.28
_cell_measurement_theta_min      2.18
_cell_volume                     4219.25(18)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SMART'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEX CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0365
_diffrn_reflns_av_sigmaI/netI    0.0087
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            14562
_diffrn_reflns_theta_full        28.28
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    26.866
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'via SADABS (Bruker, 2000)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    6.175
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       cuboid
_exptl_crystal_F_000             6647
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.06
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.932
_refine_diff_density_min         -1.016
_refine_diff_density_rms         0.192
_refine_ls_extinction_coef       0.000062(5)
_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   1.580
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     23
_refine_ls_number_reflns         316
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.580
_refine_ls_R_factor_all          0.0208
_refine_ls_R_factor_gt           0.0208
_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^)+(0.0000P)^2^+289.3677P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0483
_refine_ls_wR_factor_ref         0.0483
_reflns_number_gt                316
_reflns_number_total             316
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja809084n_si_001_4.cif
_cod_data_source_block           eb240d1
_cod_original_sg_symbol_H-M      Fm-3m
_cod_database_code               4104279