Incommensurately modulated lanthanide coinage-metal diarsenides. II. GdCuAs~2~, GdAu~1{-~δ}As~2~ and TbAu~1{-~δ}As~2~ ‒ new distortion variants of the HfCuSi~2~ type with irregularly stacked zigzag chains of arsenic atoms
Rutzinger, D.; Bartsch, C.; Doert, Th.; Ruck, M.; Acta Crystallographica Section B 65 (2009) 527–534; doi:10.1107/S0108768109029565

data_2104419
_publ_section_title
;
 Incommensurately modulated lanthanide coinage-metal diarsenides. II.
 GdCuAs~2~, GdAu~1{-~\d}As~2~ and TbAu~1{-~\d}As~2~ -- new distortion
 variants of the HfCuSi~2~ type with irregularly stacked zigzag chains
 of arsenic atoms
;
_journal_coeditor_code           CK5036
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              527
_journal_page_last               534
_journal_paper_doi               10.1107/S0108768109029565
_journal_volume                  65
_journal_year                    2009
_chemical_formula_analytical     'As2 Cu1 Gd1'
_chemical_formula_iupac          'As2 Cu1 Gd1'
_chemical_formula_moiety         'As2 Cu1 Gd1'
_chemical_formula_structural     'As2 Cu1 Gd1'
_chemical_formula_sum            'As2 Cu Gd'
_chemical_formula_weight         370.6
_chemical_name_common            'Gadulinium copper arsenide'
_chemical_name_systematic        ' ?'
_space_group_ssg_name            P21/m(\a0\g)00
_symmetry_cell_setting           monoclinic
_cell_angle_alpha                90
_cell_angle_beta                 90.05(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   3.9041(8)
_cell_length_b                   3.9015(8)
_cell_length_c                   9.908(2)
_cell_measurement_reflns_used    10083
_cell_measurement_temperature    293.0(10)
_cell_measurement_theta_max      33.53
_cell_measurement_theta_min      3.01
_cell_modulation_dimension       1
_cell_volume                     150.92(5)
_computing_cell_refinement       'X-AREA, STOE, 2006'
_computing_data_collection       'X-AREA, STOE, 2006'
_computing_data_reduction        'X-AREA, STOE, 2002'
_computing_molecular_graphics
;
DIAMOND-Visuelles Informationssystem f\"ur Kristallstrukturen
 (G. Bergerhoff, Bonn, 1999)
;
_computing_publication_material
'Jana2000 (Petricek, Dusek & Palatinus, 2000)'
_computing_structure_refinement
'Jana2000 (Petricek, Dusek & Palatinus, 2000)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293
_diffrn_detector_area_resol_mean 6.67
_diffrn_measured_fraction_theta_full 0.99
_diffrn_measurement_device       '2-circle goniometer'
_diffrn_measurement_device_type  'STOE IPDS 2'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  'plane graphite'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0941
_diffrn_reflns_av_sigmaI/netI    0.0419
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_index_m_1_max 1
_diffrn_reflns_limit_index_m_1_min -1
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            10072
_diffrn_reflns_reduction_process
;
XShape (Stoe, 1999), XRed32 (Stoe, 2001)
;
_diffrn_reflns_theta_full        34.15
_diffrn_reflns_theta_max         34.15
_diffrn_reflns_theta_min         3.05
_exptl_absorpt_coefficient_mu    50.253
_exptl_absorpt_correction_T_max  0.460
_exptl_absorpt_correction_T_min  0.128
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
'(Jana2000; Petricek, Dusek & Palatinus, 2000)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    8.153
_exptl_crystal_density_method    none
_exptl_crystal_description       platelet
_exptl_crystal_F_000             318
_exptl_crystal_size_max          0.260
_exptl_crystal_size_mid          0.060
_exptl_crystal_size_min          0.020
_refine_diff_density_max         1.64
_refine_diff_density_min         -1.97
_refine_ls_extinction_coef       0.140(10)
_refine_ls_extinction_method
'B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)'
_refine_ls_goodness_of_fit_ref   1.24
_refine_ls_number_parameters     77
_refine_ls_number_reflns         2043
_refine_ls_R_factor_all          0.1038
_refine_ls_R_factor_gt           0.0392
_refine_ls_shift/su_max          0.0224
_refine_ls_shift/su_mean         0.0073
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     w=1/(\s^2^(F)+0.0001F^2^)
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_gt          0.0362
_refine_ls_wR_factor_ref         0.0391
_reflns_number_gt                751
_reflns_number_total             2043
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            ck5036.cif
_cod_data_source_block           I
_cod_original_formula_sum        'As2 Cu1 Gd1'
_cod_database_code               2104419
_cod_database_fobs_code          2104419