Switching from positive to negative axial thermal expansion in two organic crystalline compounds with similar packing.
Negi, Lalita; Shrivastava, Ashutosh; Das, Dinabandhu; Chemical communications (Cambridge, England) 54 (2018) 10675–10678; doi:10.1039/c8cc05859h

data_7122154
_publ_section_title
;
 Switching from positive to negative axial thermal expansion in two
 organic crystalline compounds with similar packing.
;
_journal_issue                   76
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              10675
_journal_page_last               10678
_journal_paper_doi               10.1039/c8cc05859h
_journal_volume                  54
_journal_year                    2018
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C18 H16 O2'
_chemical_formula_sum            'C18 H16 O2'
_chemical_formula_weight         264.31
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2018/3
_audit_update_record
;
2018-07-14 deposited with the CCDC.
2018-08-10 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.9061(3)
_cell_length_b                   7.3412(5)
_cell_length_c                   32.9746(19)
_cell_measurement_reflns_used    5655
_cell_measurement_temperature    250(2)
_cell_measurement_theta_max      27.72
_cell_measurement_theta_min      2.47
_cell_volume                     1429.71(15)
_computing_data_collection       'Bruker APEX-III'
_computing_data_reduction        'Bruker SAINT '
_computing_molecular_graphics    'XSEED (Barbour 2017)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      250(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Bruker APEX-II CMOS detector'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0327
_diffrn_reflns_av_unetI/netI     0.0552
_diffrn_reflns_Laue_measured_fraction_full 0.992
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       44
_diffrn_reflns_limit_l_min       -43
_diffrn_reflns_number            8656
_diffrn_reflns_point_group_measured_fraction_full 0.985
_diffrn_reflns_point_group_measured_fraction_max 0.981
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         28.313
_diffrn_reflns_theta_min         2.471
_diffrn_source                   microfocus
_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_T_max  0.7457
_exptl_absorpt_correction_T_min  0.6730
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.228
_exptl_crystal_density_meas      ?
_exptl_crystal_description       'HEXAGONAL PLATE'
_exptl_crystal_F_000             560
_exptl_crystal_size_max          0.360
_exptl_crystal_size_mid          0.320
_exptl_crystal_size_min          0.090
_refine_diff_density_max         0.191
_refine_diff_density_min         -0.179
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details
;
 Flack x determined using 786 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.2(7)
_refine_ls_extinction_coef       0.019(4)
_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   0.996
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         3492
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.996
_refine_ls_R_factor_all          0.0810
_refine_ls_R_factor_gt           0.0433
_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^)+(0.0763P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1058
_refine_ls_wR_factor_ref         0.1301
_reflns_Friedel_coverage         0.676
_reflns_Friedel_fraction_full    0.975
_reflns_Friedel_fraction_max     0.963
_reflns_number_gt                2411
_reflns_number_total             3492
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8cc05859h2.cif
_cod_data_source_block           2_250K
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 4973 2017-02-22 13:04:09Z antanas 

 Adding full bibliography for 7122148--7122167.cif.
;
_cod_database_code               7122154
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.972
_shelx_estimated_absorpt_t_max   0.993
_shelx_res_checksum              88309