Discrete CH···N Bonded Patterns Modified by Temperature and Pressure in Four Pyrazine Polymorphs
Patyk, Ewa; Podsiadło, Marcin; Katrusiak, Andrzej; Crystal Growth & Design 15 (2015) 5670–; doi:10.1021/acs.cgd.5b01475

data_4516578
_publ_section_title
;
 Discrete CH&#x00B7;&#x00B7;&#x00B7;N Bonded Patterns Modified by
 Temperature and Pressure in Four Pyrazine Polymorphs
;
_journal_issue                   12
_journal_name_full               'Crystal Growth &amp; Design'
_journal_page_first              5670
_journal_paper_doi               10.1021/acs.cgd.5b01475
_journal_volume                  15
_journal_year                    2015
_chemical_formula_moiety         'C4 H4 N2'
_chemical_formula_sum            'C4 H4 N2'
_chemical_formula_weight         80.09
_chemical_melting_point          325
_chemical_name_common            pyrazine
_chemical_name_systematic
; 
pyrazine phase IV
;
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 96.15(14)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.265(11)
_cell_length_b                   5.433(7)
_cell_length_c                   3.479(4)
_cell_measurement_reflns_used    703
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      27.92
_cell_measurement_theta_min      5.81
_cell_volume                     174.1(4)
_computing_cell_refinement       'CrysAlisRED (Oxford Diffraction, 2004)'
_computing_data_collection       'CrysAlisCCD (Oxford Diffraction, 2004)'
_computing_data_reduction
'CrysAlisRED (Oxford Diffraction, 2004); REDSHABS (Katrusiak, A.  2003)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 1990)'
_computing_publication_material  'SHELXL--97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL--97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS--97 (Sheldrick, 1997)'
_diffrn_ambient_environment      'diamond-anvil cell'
_diffrn_ambient_pressure         2390000
_diffrn_ambient_temperature      295(2)
_diffrn_measured_fraction_theta_full 0.248
_diffrn_measured_fraction_theta_max 0.248
_diffrn_measurement_device_type  'KM-4 CCD'
_diffrn_measurement_method       '\f- and \w-scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0599
_diffrn_reflns_av_sigmaI/netI    0.0291
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       3
_diffrn_reflns_limit_k_min       -3
_diffrn_reflns_limit_l_max       4
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            703
_diffrn_reflns_theta_full        27.92
_diffrn_reflns_theta_max         27.92
_diffrn_reflns_theta_min         5.81
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.101
_exptl_absorpt_correction_T_max  0.94
_exptl_absorpt_correction_T_min  0.63
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
; 
 Correction for absorption of the diamond-anvil cell and the sample 
 were made using program REDSHABS (Katrusiak, A. (2003) REDSHABS. Adam
 Mickiewicz University Pozna\'n; Katrusiak, A. (2004) Z. Kristallogr.
 219, 461-467).
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.528
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       cylinder
_exptl_crystal_F_000             84
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.36
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.077
_refine_diff_density_min         -0.071
_refine_diff_density_rms         0.020
_refine_ls_extinction_coef       0.75(8)
_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   1.242
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     29
_refine_ls_number_reflns         104
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.205
_refine_ls_R_factor_all          0.0487
_refine_ls_R_factor_gt           0.0293
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+0.0680P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0445
_refine_ls_wR_factor_ref         0.0499
_reflns_number_gt                87
_reflns_number_total             104
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cg5b01475_si_002.cif
_cod_data_source_block           phaseIV_2.39GPa
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4516578