Narrowing the gap: from semiconductor to semimetal in the homologous series of rare-earth zinc arsenides RE2-yZn4As4·n(REAs) and Mn-substituted derivatives RE2-yMnxZn4-xAs4·n(REAs) (RE = La-Nd, Sm, Gd).
Lin, Xinsong; Tabassum, Danisa; Mar, Arthur; Dalton transactions (Cambridge, England : 2003) 44 (2015) 20254–20264; doi:10.1039/c5dt03596a

data_7037021
_publ_section_title
;
 Narrowing the gap: from semiconductor to semimetal in the homologous
 series of rare-earth zinc arsenides RE2-yZn4As4&#x00B7;n(REAs) and
 Mn-substituted derivatives RE2-yMnxZn4-xAs4&#x00B7;n(REAs) (RE = La-Nd,
 Sm, Gd).
;
_journal_issue                   46
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              20254
_journal_page_last               20264
_journal_paper_doi               10.1039/c5dt03596a
_journal_volume                  44
_journal_year                    2015
_chemical_formula_structural     'Sm5.40 Zn4 As8'
_chemical_formula_sum            'As8 Sm5.4 Zn4'
_chemical_formula_weight         1672.73
_chemical_name_common            'samarium zinc arsenide (5.4/4/8)'
_chemical_name_systematic        'samarium zinc arsenide (5.4/4/8)'
_space_group_crystal_system      trigonal
_space_group_IT_number           166
_space_group_name_Hall           '-R 3 2"'
_space_group_name_H-M_alt        'R -3 m :H'
_symmetry_space_group_name_Hall  '-R 3 2"'
_symmetry_space_group_name_H-M   'R -3 m :H'
_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                120
_cell_formula_units_Z            3
_cell_length_a                   4.1689(4)
_cell_length_b                   4.1689(4)
_cell_length_c                   82.103(9)
_cell_measurement_reflns_used    2576
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      32.77
_cell_measurement_theta_min      5.22
_cell_volume                     1235.8(2)
_computing_cell_refinement       'Bruker SAINT 7.68A (Bruker, 2009)'
_computing_data_collection       'Bruker APEX 2 (Bruker, 2008)'
_computing_data_reduction        'Bruker SAINT 7.68A'
_computing_molecular_graphics    'ATOMS 5.1 (Dowty, 1999)'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.999
_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  0.0385
_diffrn_reflns_av_unetI/netI     0.0188
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.999
_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       123
_diffrn_reflns_limit_l_min       -123
_diffrn_reflns_number            5971
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.018
_diffrn_reflns_theta_min         1.488
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    40.532
_exptl_absorpt_correction_T_max  0.4055
_exptl_absorpt_correction_T_min  0.1269
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'Bruker SHELXTL (Sheldrick, 2013)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    6.743
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       irregular
_exptl_crystal_F_000             2156
_exptl_crystal_size_max          0.065
_exptl_crystal_size_mid          0.057
_exptl_crystal_size_min          0.028
_refine_diff_density_max         2.460
_refine_diff_density_min         -3.530
_refine_diff_density_rms         0.344
_refine_ls_extinction_coef       0.000178(16)
_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   1.121
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     33
_refine_ls_number_reflns         715
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.121
_refine_ls_R_factor_all          0.0341
_refine_ls_R_factor_gt           0.0255
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0164P)^2^+27.8812P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0495
_refine_ls_wR_factor_ref         0.0531
_reflns_Friedel_coverage         0.000
_reflns_number_gt                595
_reflns_number_total             715
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c5dt03596a8.cif
_cod_data_source_block           Sm6-xZn4As8
_cod_depositor_comments
'Adding full bibliography for 7037017--7037025.cif.'
_cod_original_cell_volume        1235.8(3)
_cod_original_formula_sum        'As8 Sm5.40 Zn4'
_cod_database_code               7037021
_shelx_estimated_absorpt_t_min   0.178
_shelx_estimated_absorpt_t_max   0.397
_shelxl_version_number           2013-4
_shelx_res_checksum              92341
_shelx_hkl_checksum              99242