Quaternary rare-earth arsenides REAg1−Zn As2 (RE=La‒Nd, Sm, Gd‒Dy) with tetragonal SrZnBi2- and HfCuSi2-type structures
Ramachandran, Krishna K.; Genet, Clément; Mar, Arthur; Journal of Solid State Chemistry 231 (2015) 204–211; doi:10.1016/j.jssc.2015.08.032

data_1561728
_publ_section_title
;
 Quaternary rare-earth arsenides REAg1&#x2212;Zn As2 (RE=La--Nd, Sm,
 Gd--Dy) with tetragonal SrZnBi2- and HfCuSi2-type structures
;
_journal_name_full               'Journal of Solid State Chemistry'
_journal_page_first              204
_journal_page_last               211
_journal_paper_doi               10.1016/j.jssc.2015.08.032
_journal_volume                  231
_journal_year                    2015
_chemical_formula_structural     'Pr Ag0.50 Zn0.50 As2'
_chemical_formula_sum            'Ag0.5 As2 Pr Zn0.5'
_chemical_formula_weight         377.37
_chemical_name_common
'praseodymium silver zinc arsenide (1/0.5/0.5/2)'
_chemical_name_systematic
'praseodymium silver zinc arsenide (1/0.5/0.5/2)'
_space_group_crystal_system      tetragonal
_space_group_IT_number           129
_space_group_name_Hall           '-P 4a 2a'
_space_group_name_H-M_alt        'P 4/n m m :2'
_atom_sites_solution_hydrogens   .
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   4.0536(4)
_cell_length_b                   4.0536(4)
_cell_length_c                   10.3542(9)
_cell_measurement_reflns_used    1969
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      32.91
_cell_measurement_theta_min      5.40
_cell_volume                     170.14(3)
_computing_cell_refinement       'Bruker SAINT 8.34A (Bruker, 2013)'
_computing_data_collection       'Bruker APEX 2 (Bruker, 2008)'
_computing_data_reduction        'Bruker SAINT 8.34A'
_computing_molecular_graphics    'ATOMS 5.1 (Dowty, 1999)'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker PLATFORM/SMART APEX II CCD'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0423
_diffrn_reflns_av_unetI/netI     0.0146
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            2378
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.147
_diffrn_reflns_theta_min         1.967
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    39.556
_exptl_absorpt_correction_T_max  0.3105
_exptl_absorpt_correction_T_min  0.1706
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'Bruker SHELXTL (Sheldrick, 2013)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    7.366
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       irregular
_exptl_crystal_F_000             327
_exptl_crystal_size_max          0.077
_exptl_crystal_size_mid          0.057
_exptl_crystal_size_min          0.046
_refine_diff_density_max         1.809
_refine_diff_density_min         -1.489
_refine_diff_density_rms         0.219
_refine_ls_extinction_coef       0.0037(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   1.170
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     12
_refine_ls_number_reflns         236
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.170
_refine_ls_R_factor_all          0.0174
_refine_ls_R_factor_gt           0.0167
_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^)+(0.0126P)^2^+0.8949P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0364
_refine_ls_wR_factor_ref         0.0366
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                228
_reflns_number_total             236
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            JSSC-2015-231-204.cif
_cod_data_source_block           PrAgZnAs
_cod_original_cell_volume        170.14(4)
_cod_original_sg_symbol_H-M      'P 4/n m m'
_cod_original_formula_sum        'Ag0.50 As2 Pr Zn0.50'
_cod_database_code               1561728
_shelx_estimated_absorpt_t_min   0.151
_shelx_estimated_absorpt_t_max   0.263
_shelxl_version_number           2013-4
_shelx_res_checksum              65991
_shelx_hkl_checksum              12336