Quaternary Arsenides AM1.5Tt0.5As2 (A= Na, K, Rb; M= Zn, Cd; Tt= Si, Ge, Sn): Size Effects in CaAl2Si2- and ThCr2Si2-Type Structures
Mansura Khatun; Stanislav S. Stoyko; Arthur Mar; Inorganic Chemistry 52 (2013) 3148–3158; doi:10.1021/ic302627n

data_4334196
_publ_contact_author_address
; Department of Chemistry
  University of Alberta
  Edmonton, AB
  Canada  T6G 2G2
;
_publ_contact_author_email       arthur.mar@ualberta.ca
_publ_contact_author_fax         '(780) 492-8231'
_publ_contact_author_name        'Dr. Arthur Mar'
_publ_contact_author_phone       '(780) 492-5592'
_publ_section_title
;
 Quaternary Arsenides AM1.5Tt0.5As2 (A= Na, K, Rb; M= Zn, Cd; Tt= Si, Ge,
 Sn): Size Effects in CaAl2Si2- and ThCr2Si2-Type Structures
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              3148
_journal_page_last               3158
_journal_paper_doi               10.1021/ic302627n
_journal_volume                  52
_journal_year                    2013
_chemical_formula_structural     'K Zn1.5 Ge0.5 As2'
_chemical_formula_sum            'As2 Ge0.5 K Zn1.5'
_chemical_formula_weight         323.29
_chemical_name_common
'Potassium zinc germanium arsenide (1/1.5/0.5/2)'
_chemical_name_systematic
'Potassium zinc germanium arsenide (1/1.5/0.5/2)'
_space_group_IT_number           139
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-I 4 2'
_symmetry_space_group_name_H-M   'I 4/m m m'
_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            2
_cell_length_a                   4.0872(4)
_cell_length_b                   4.0872(4)
_cell_length_c                   14.3117(15)
_cell_measurement_reflns_used    1925
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      32.04
_cell_measurement_theta_min      2.85
_cell_volume                     239.08(4)
_computing_cell_refinement       'Bruker SAINT 7.68A (Bruker, 2009)'
_computing_data_collection       'Bruker SMART 5.054 (Bruker, 1999)'
_computing_data_reduction        'Bruker SAINT 7.68A'
_computing_molecular_graphics    'ATOMS 5.1 (Dowty, 1999)'
_computing_publication_material  'Bruker SHELXTL 6.12'
_computing_structure_refinement  'Bruker SHELXTL 6.12'
_computing_structure_solution    'Bruker SHELXTL 6.12'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker PLATFORM APEX II CCD'
_diffrn_measurement_method       '\w 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  0.0192
_diffrn_reflns_av_sigmaI/netI    0.0104
_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       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            1691
_diffrn_reflns_theta_full        33.11
_diffrn_reflns_theta_max         33.11
_diffrn_reflns_theta_min         2.85
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    25.071
_exptl_absorpt_correction_T_max  0.6337
_exptl_absorpt_correction_T_min  0.1914
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'Bruker SHELXTL 6.12 (Sheldrick, 2001)'
_exptl_crystal_colour            grey
_exptl_crystal_density_diffrn    4.491
_exptl_crystal_description       prism
_exptl_crystal_F_000             292
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.03
_refine_diff_density_max         1.234
_refine_diff_density_min         -1.078
_refine_diff_density_rms         0.142
_refine_ls_extinction_coef       0.0094(11)
_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   1.183
_refine_ls_matrix_type           full
_refine_ls_number_parameters     9
_refine_ls_number_reflns         171
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.183
_refine_ls_R_factor_all          0.0211
_refine_ls_R_factor_gt           0.0199
_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^+1.9044P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0379
_refine_ls_wR_factor_ref         0.0381
_reflns_number_gt                160
_reflns_number_total             171
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ic302627n_si_002_10.cif
_cod_data_source_block           KZn1.5Ge0.5As2
_cod_original_formula_sum        'As2 Ge0.50 K Zn1.50'
_cod_database_code               4334196