Synthesis, Structural Characterization, and Physical Properties of the Early Rare-Earth Metal Digermanides REGe2-x (x~ 1/4) [RE= La-Nd, Sm]. A Case Study of Commensurately and Incommensurately Modulated Structures
Jiliang Zhang; Paul H. Tobash; William D. Pryz; Douglas J. Buttey; Namjung Hur; Joe D. Thompson; John L. Sarrao; Svilen Bobev; Inorganic Chemistry 52 (2013) 953–964; doi:10.1021/ic3021645

data_4333603
_publ_section_title
;
 Synthesis, Structural Characterization, and Physical Properties of the
 Early Rare-Earth Metal Digermanides REGe2-x (x~ 1/4) [RE= La-Nd, Sm]. A
 Case Study of Commensurately and Incommensurately Modulated Structures
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              953
_journal_page_last               964
_journal_paper_doi               10.1021/ic3021645
_journal_volume                  52
_journal_year                    2013
_chemical_formula_sum            'Ge7 Sm4'
_chemical_formula_weight         1109.53
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           20
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'C 2c 2'
_symmetry_space_group_name_H-M   'C 2 2 21'
_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                   5.892(2)
_cell_length_b                   13.781(5)
_cell_length_c                   11.792(5)
_cell_measurement_reflns_used    517
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.59
_cell_measurement_theta_min      5.11
_cell_volume                     957.5(6)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_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      120(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  '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  0.0475
_diffrn_reflns_av_sigmaI/netI    0.0327
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            5124
_diffrn_reflns_theta_full        26.37
_diffrn_reflns_theta_max         26.37
_diffrn_reflns_theta_min         2.96
_exptl_absorpt_coefficient_mu    45.641
_exptl_absorpt_correction_T_max  0.3413
_exptl_absorpt_correction_T_min  0.2087
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            silver
_exptl_crystal_density_diffrn    7.696
_exptl_crystal_description       plate
_exptl_crystal_F_000             1888
_exptl_crystal_size_max          0.05
_exptl_crystal_size_mid          0.03
_exptl_crystal_size_min          0.03
_refine_diff_density_max         2.573
_refine_diff_density_min         -2.519
_refine_diff_density_rms         0.526
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.3(3)
_refine_ls_extinction_coef       0.00003(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   1.163
_refine_ls_matrix_type           full
_refine_ls_number_parameters     53
_refine_ls_number_reflns         988
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.163
_refine_ls_R_factor_all          0.0384
_refine_ls_R_factor_gt           0.0345
_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^)+(0.0361P)^2^+13.7911P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0839
_refine_ls_wR_factor_ref         0.0864
_reflns_number_gt                920
_reflns_number_total             988
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic3021645_si_002.cif
_cod_data_source_block           final
_cod_original_cell_volume        957.6(6)
_cod_database_code               4333603