Crystal structure across the β to α phase transition in thermoelectric Cu<sub>2-<i>x</i></sub> Se.
Eikeland, Espen; Blichfeld, Anders B.; Borup, Kasper A.; Zhao, Kunpeng; Overgaard, Jacob; Shi, Xun; Chen, Lidong; Iversen, Bo B.; IUCrJ 4 (2017) 476–485; doi:10.1107/S2052252517005553

data_1556747
_publ_section_title
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 Crystal structure across the \b to \a phase transition in thermoelectric
 Cu<sub>2-<i>x</i></sub> Se.
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_journal_coeditor_code           LC5071SUP1
_journal_issue                   'Pt 4'
_journal_name_full               IUCrJ
_journal_page_first              476
_journal_page_last               485
_journal_paper_doi               10.1107/S2052252517005553
_journal_volume                  4
_journal_year                    2017
_chemical_formula_moiety         '0.33(Cu5.85 Se3)'
_chemical_formula_sum            'Cu1.95 Se'
_chemical_formula_weight         202.86
_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'
_audit_creation_date             2017-01-24
_audit_creation_method
;
Olex2 1.2
(compiled 2017.01.04 svn.r3372 for OlexSys, GUI svn.r5292)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            6
_cell_length_a                   4.0922(10)
_cell_length_b                   4.0922(10)
_cell_length_c                   20.459(9)
_cell_measurement_reflns_used    679
_cell_measurement_temperature    99.98(12)
_cell_measurement_theta_max      31.5010
_cell_measurement_theta_min      2.9880
_cell_volume                     296.71(17)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
(compiled Aug 13 2014,18:06:01)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
(compiled Aug 13 2014,18:06:01)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
(compiled Aug 13 2014,18:06:01)
;
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      99.98(12)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 10.3590
_diffrn_detector_type            Atlas
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_details
;
  1 omega -120.00   14.00   1.0000  140.0000
omega____ theta____ kappa____ phi______ frames
    -      -28.1866  -57.0000  -60.0000 134

  2 omega  -65.00   84.00   1.0000  140.0000
omega____ theta____ kappa____ phi______ frames
    -       26.9366  -30.0000 -102.0000 149

  3 omega  -15.00  119.00   1.0000  140.0000
omega____ theta____ kappa____ phi______ frames
    -       26.9366   57.0000 -150.0000 134

  4 omega -120.00  -95.00   1.0000  140.0000
omega____ theta____ kappa____ phi______ frames
    -      -28.1866  -57.0000   30.0000 25

  5 omega  -95.00   -3.00   1.0000  140.0000
omega____ theta____ kappa____ phi______ frames
    -      -28.1866  126.0000  116.0000 92
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'SuperNova, Single source at offset, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_UB_11      -0.1937414000
_diffrn_orient_matrix_UB_12      -0.1213500000
_diffrn_orient_matrix_UB_13      -0.0076646000
_diffrn_orient_matrix_UB_21      0.0432485000
_diffrn_orient_matrix_UB_22      0.0151120000
_diffrn_orient_matrix_UB_23      -0.0337996000
_diffrn_orient_matrix_UB_31      0.0263182000
_diffrn_orient_matrix_UB_32      -0.1578670000
_diffrn_orient_matrix_UB_33      0.0023816000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1071
_diffrn_reflns_av_unetI/netI     0.0418
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            754
_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         26.268
_diffrn_reflns_theta_min         2.987
_diffrn_source                   'SuperNova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    38.848
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.09788
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
(compiled Aug 13 2014,18:06:01)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'metallic grayish black'
_exptl_crystal_colour_lustre     metallic
_exptl_crystal_colour_modifier   grayish
_exptl_crystal_colour_primary    black
_exptl_crystal_density_diffrn    6.812
_exptl_crystal_description       irregular
_exptl_crystal_F_000             543
_exptl_crystal_size_max          0.0908
_exptl_crystal_size_mid          0.0493
_exptl_crystal_size_min          0.0167
_refine_diff_density_max         1.580
_refine_diff_density_min         -1.620
_refine_diff_density_rms         0.409
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.290
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     19
_refine_ls_number_reflns         100
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.282
_refine_ls_R_factor_all          0.0631
_refine_ls_R_factor_gt           0.0631
_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^)+(0.0533P)^2^+46.1849P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1522
_refine_ls_wR_factor_ref         0.1522
_reflns_Friedel_coverage         0.000
_reflns_number_gt                100
_reflns_number_total             100
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            lc5071.cif
_cod_data_source_block           Cu1p95Se_CVT1_100K
_cod_original_cell_volume        296.7(2)
_cod_original_sg_symbol_H-M      'R -3 m'
_cod_database_code               1556747
_shelx_shelxl_version_number     2014/7
_chemical_oxdiff_formula         Cu2Se
_reflns_odcompleteness_completeness 100.00
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_olex2_refinement_description
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1. Others
 1*[Sof(Cu1A)]+1*[Sof(Cu1B)]+3*[Sof(Cu2)]=1.95 with esd of 0.01
 Fixed X: Se1(0.333301) Cu1B(0.6667) Cu1A(0.6667)
 Fixed Y: Se1(0.6667) Cu1B(0.333301) Cu1A(0.333301)
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