Crystal structure of ω-Al~4~Cr
Fan, Changzeng; Liu, Cong; IUCrData 3 (2018) x180216–; doi:10.1107/S241431461800216X

data_1548892
_publ_section_title
;
 Crystal structure of \w-Al~4~Cr
;
_journal_coeditor_code           WM4068
_journal_issue                   2
_journal_name_full               IUCrData
_journal_page_first              x180216
_journal_paper_doi               10.1107/S241431461800216X
_journal_volume                  3
_journal_year                    2018
_chemical_formula_iupac          'Al4 Cr'
_chemical_formula_sum            'Al4 Cr'
_chemical_formula_weight         159.92
_chemical_name_systematic
;
Tetraaluminium chromium
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           8
_space_group_name_Hall           'C -2y'
_space_group_name_H-M_alt        'C 1 m 1'
_symmetry_space_group_name_Hall  'C -2y'
_symmetry_space_group_name_H-M   'C 1 m 1'
_cell_angle_alpha                90
_cell_angle_beta                 100.357(4)
_cell_angle_gamma                90
_cell_formula_units_Z            6
_cell_length_a                   5.1574(6)
_cell_length_b                   17.413(2)
_cell_length_c                   5.1107(7)
_cell_measurement_reflns_used    1199
_cell_measurement_temperature    293.(2)
_cell_measurement_theta_max      27.0053
_cell_measurement_theta_min      4.0533
_cell_volume                     451.49(10)
_computing_cell_refinement
;
SAINT (Bruker, 2015)
;
_computing_data_collection
;
APEX3 (Bruker, 2015)
;
_computing_data_reduction
;
SAINT (Bruker, 2015)
;
_computing_molecular_graphics
;
DIAMOND  (Brandenburg & Putz, 2017)
;
_computing_publication_material
;
publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015b)
;
_computing_structure_solution
;
SHELXT2014 (Sheldrick, 2015a)
;
_diffrn_ambient_temperature      293.(2)
_diffrn_detector_area_resol_mean 10.4167
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEXII Photon 100 COMS'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  Graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0678
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            4792
_diffrn_reflns_theta_full        28.93
_diffrn_reflns_theta_max         28.93
_diffrn_reflns_theta_min         2.34
_exptl_absorpt_coefficient_mu    4.646
_exptl_absorpt_correction_T_max  0.870
_exptl_absorpt_correction_T_min  0.757
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(<i>SADABS</i>; Krause <i>et al.</i>,  2015)
;
_exptl_crystal_colour            metallic
_exptl_crystal_density_diffrn    3.529
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             456
_exptl_crystal_size_max          0.07
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.848
_refine_diff_density_min         -1.203
_refine_ls_abs_structure_details
;
Flack (1983); 584 Friedel pairs
;
_refine_ls_abs_structure_Flack   0.16(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     74
_refine_ls_number_reflns         1200
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.050
_refine_ls_R_factor_all          0.0721
_refine_ls_R_factor_gt           0.0466
_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^)+(0.0320P)^2^+2.4184P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0833
_refine_ls_wR_factor_ref         0.0903
_reflns_number_gt                967
_reflns_number_total             1200
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            wm4068sup1.cif
_cod_data_source_block           I
_cod_database_code               1548892
_shelx_hkl_checksum              451
_shelx_res_checksum              48236
_cod_database_fobs_code 1548892