On the importance of low-frequency modes in predicting pressure-induced phase transitions.
Hoser, Anna; Zwolenik, Aleksandra; Makal, Anna; Physical chemistry chemical physics : PCCP 26 (2024) 20745–20749; doi:10.1039/d4cp02368d

data_7249111
_publ_section_title
;
 On the importance of low-frequency modes in predicting pressure-induced
 phase transitions.
;
_journal_issue                   31
_journal_name_full               'Physical chemistry chemical physics : PCCP'
_journal_page_first              20745
_journal_page_last               20749
_journal_paper_doi               10.1039/d4cp02368d
_journal_volume                  26
_journal_year                    2024
_chemical_formula_moiety         'C20 H14 O2'
_chemical_formula_sum            'C20 H14 O2'
_chemical_formula_weight         286.31
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2024-01-27
_audit_creation_method
;
Olex2 1.5-alpha
(compiled 2023.11.24 svn.r209d9fb for OlexSys, GUI svn.r6869)
;
_audit_update_record
;
2024-02-13 deposited with the CCDC.	2024-07-24 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 100.1(4)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   9.16(4)
_cell_length_b                   7.308(4)
_cell_length_c                   10.05(4)
_cell_measurement_reflns_used    459
_cell_measurement_temperature    290.7(7)
_cell_measurement_theta_max      23.1100
_cell_measurement_theta_min      2.7690
_cell_volume                     662(4)
_computing_cell_refinement       'CrysAlisPro 1.171.42.49 (Rigaku OD, 2022)'
_computing_data_collection       'CrysAlisPro 1.171.42.49 (Rigaku OD, 2022)'
_computing_data_reduction        'CrysAlisPro 1.171.42.49 (Rigaku OD, 2022)'
_computing_molecular_graphics    'Olex2 1.5-alpha (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-alpha (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2013/2 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_pressure         560000
_diffrn_ambient_temperature      291.15
_diffrn_crystal_treatment
'pressurized slowly/rapidly in paratone oil as a hydrostatic medium'
_diffrn_detector_area_resol_mean 5.2195
_diffrn_detector_type            Atlas
_diffrn_measured_fraction_theta_full 0.324
_diffrn_measured_fraction_theta_max 0.311
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
  1  \w    -15.00  23.00   1.00  120.00    --    9.85  39.00 -12.00   38
  2  \w     -3.00  35.00   1.00  120.00    --    9.85   0.00   0.00   38
  3  \w    -20.00   9.00   1.00  120.00    --    9.85  67.00 157.00   29
  4  \w      1.00  28.00   1.00  120.00    --    9.85 -26.00-172.00   27
  5  \w    -15.00  35.00   1.00  120.00    --    9.85 -26.00   7.00   50
  6  \w     22.00  59.00   1.00  120.00    --    9.85-114.00  45.00   37
  7  \w    -40.00 -15.00   1.00  120.00    --    9.85 114.00 135.00   25
  8  \w    -31.00  -5.00   1.00  120.00    --    9.85   0.00-150.00   26
  9  \w    -36.00 -10.00   1.00  120.00    --  -11.80  39.00 -12.00   26
 10  \w    -61.00 -51.00   1.00  120.00    --  -11.80 114.00 -45.00   10
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at home/near, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_measurement_specimen_support
'Diamond Anvil Cell, effective opening angle of 40 deg.'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1386
_diffrn_reflns_av_unetI/netI     0.1142
_diffrn_reflns_Laue_measured_fraction_full 0.324
_diffrn_reflns_Laue_measured_fraction_max 0.311
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            1922
_diffrn_reflns_point_group_measured_fraction_full 0.324
_diffrn_reflns_point_group_measured_fraction_max 0.311
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.196
_diffrn_reflns_theta_min         2.778
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  0.89437
_exptl_absorpt_correction_T_min  0.89437
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.42.49 (Rigaku Oxford Diffraction, 2022)
Spherical absorption correction
using equivalent radius and absorption coefficient.
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear yellow'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    1.436
_exptl_crystal_description       plate
_exptl_crystal_F_000             300
_exptl_crystal_preparation
'Mounted in a Diamond-Anvil Cell using paratone oil as pressure medium.'
_exptl_crystal_pressure_history  'Pressurized to 0.56 GPa.'
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.09
_exptl_crystal_size_rad          0.400
_refine_diff_density_max         0.142
_refine_diff_density_min         -0.127
_refine_diff_density_rms         0.035
_refine_ls_extinction_coef       0.028(13)
_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   1.047
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     102
_refine_ls_number_reflns         414
_refine_ls_number_restraints     78
_refine_ls_restrained_S_all      0.950
_refine_ls_R_factor_all          0.1404
_refine_ls_R_factor_gt           0.0544
_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^)+(0.0660P)^2^+0.0988P]
 where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1206
_refine_ls_wR_factor_ref         0.1705
_reflns_Friedel_coverage         0.000
_reflns_number_gt                200
_reflns_number_total             414
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d4cp02368d2.cif
_cod_data_source_block           2papa_0p5gpa
_cod_depositor_comments
'Adding full bibliography for 7249110--7249118.cif.'
_cod_database_code               7249111
_shelxl_version_number           2013-2
_shelx_estimated_absorpt_t_max   0.992
_shelx_estimated_absorpt_t_min   0.975
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Rigid body (RIGU) restrains
 All non-hydrogen atoms
 with sigma for 1-2 distances of 0.004 and sigma for 1-3 distances of 0.004
3.a Aromatic/amide H refined with riding coordinates:
 C10(H10), C11(H11), C13(H13), C14(H14)
3.b Idealised Me refined as rotating group:
 C18(H18A,H18B,H18C)
;
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;