Formation of two crystal modifications of Fe7C3−x at 5.5 GPa
Gromilov, Sergey; Chepurov, Anatoly; Sonin, Valeri; Zhimulev, Egor; Sukhikh, Aleksandr; Chepurov, Aleksei; Shcheglov, Dmitry; Journal of Applied Crystallography 52 (2019) 1378–; doi:10.1107/S1600576719013347

data_2300662
_publ_section_title
;
 Formation of two crystal modifications of Fe7C3&#x2212;x&#x000D; at
 5.5&#x2005;GPa
;
_journal_coeditor_code           GJ5230
_journal_issue                   6
_journal_name_full               'Journal of Applied Crystallography'
_journal_page_first              1378
_journal_paper_doi               10.1107/S1600576719013347
_journal_volume                  52
_journal_year                    2019
_chemical_formula_moiety         'C6 Fe14'
_chemical_formula_sum            'C6 Fe14'
_chemical_formula_weight         853.96
_chemical_name_common            'iron carbide'
_chemical_name_systematic        'iron carbide'
_space_group_crystal_system      orthorhombic
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_atom_sites_solution_primary     dual
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.9698(6)
_cell_length_b                   4.5240(2)
_cell_length_c                   13.7658(6)
_cell_measurement_reflns_used    4135
_cell_measurement_temperature    298
_cell_measurement_theta_max      33.19
_cell_measurement_theta_min      3.40
_cell_volume                     745.44(6)
_computing_cell_refinement       'Bruker SAINT V8.32B'
_computing_data_collection       'Bruker APEX2 V2013.6-2'
_computing_data_reduction        'Bruker SAINT V8.32B'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3'
_computing_structure_solution    'SHELXT 2014/5'
_diffrn_ambient_temperature      298
_diffrn_detector_area_resol_mean 25
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0290
_diffrn_reflns_av_unetI/netI     0.0210
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            6522
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.239
_diffrn_reflns_theta_min         2.960
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    26.255
_exptl_absorpt_correction_T_max  0.7465
_exptl_absorpt_correction_T_min  0.4357
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS-2012/1 (Bruker,2012) was used for absorption correction. wR2(int)
 was 0.1120 before and 0.0329 after correction. The Ratio of minimum to
 maximum transmission is 0.5837. The \l/2 correction factor is 0.0015.
;
_exptl_crystal_colour            'metallic light gray'
_exptl_crystal_density_diffrn    7.609
_exptl_crystal_description       block
_exptl_crystal_F_000             1600
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.04
_refine_diff_density_max         1.829
_refine_diff_density_min         -0.845
_refine_ls_extinction_coef       0.0031(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2018/3 (Sheldrick 2018)'
_refine_ls_goodness_of_fit_ref   1.093
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     92
_refine_ls_number_reflns         1428
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.093
_refine_ls_R_factor_all          0.0278
_refine_ls_R_factor_gt           0.0245
_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^)+(0.0360P)^2^+1.3650P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0642
_refine_ls_wR_factor_ref         0.0663
_reflns_number_gt                1268
_reflns_number_total             1428
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            gj5230sup1.cif
_cod_data_source_block           I
_cod_database_code               2300662
_shelx_estimated_absorpt_t_min   0.145
_shelx_estimated_absorpt_t_max   0.420
_shelx_hkl_checksum              52404
_shelx_res_checksum              19271