Polymorphism in pentacene
Mattheus, Christine C.; Dros, Anne B.; Baas, Jacob; Meetsma, Auke; Boer, Jan L. de; Palstra, Thomas T.M.; Acta Crystallographica Section C 57 (2001) 939–941; doi:10.1107/S010827010100703X

data_2012157
_publ_section_title
;
 Polymorphism in pentacene
;
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              939
_journal_page_last               941
_journal_paper_doi               10.1107/S010827010100703X
_journal_volume                  57
_journal_year                    2001
_chemical_formula_moiety         'C22 H14'
_chemical_formula_sum            'C22 H14'
_chemical_formula_weight         278.35
_chemical_name_systematic
;
 pentacene
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_cell_angle_alpha                76.475(4)
_cell_angle_beta                 87.682(4)
_cell_angle_gamma                84.684(4)
_cell_formula_units_Z            2
_cell_length_a                   6.2660(10)
_cell_length_b                   7.7750(10)
_cell_length_c                   14.5300(10)
_cell_measurement_reflns_used    23
_cell_measurement_temperature    293
_cell_measurement_theta_max      21.70
_cell_measurement_theta_min      17.92
_cell_volume                     685.15(15)
_computing_cell_refinement       'SET4 (de Boer & Duisenberg, 1984)'
_computing_data_collection       'CAD4-UNIX Software (Enraf-Nonius, 1994)'
_computing_data_reduction        'HELENA (Spek, 1997)'
_computing_molecular_graphics    'PLUTO (Meetsma, 2000) and PLATON (Spek, 1994)'
_computing_publication_material  'PLATON (Spek, 1990)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_full 1.0
_diffrn_measured_fraction_theta_max 1.0
_diffrn_measurement_device_type
;
     Enraf Nonius CAD-4F diffractometer
;
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  'perpendicular mounted graphite'
_diffrn_radiation_source         'fine focus sealed Philips Mo tube '
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .0340
_diffrn_reflns_av_sigmaI/netI    .1117
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            2856
_diffrn_reflns_reduction_process
;
 Intensity data were corrected for Lorentz and polarization  effects, scale
 variation, but not for absorption and reduced to F~o~^2^
;
_diffrn_reflns_theta_full        25.97
_diffrn_reflns_theta_max         25.97
_diffrn_reflns_theta_min         1.44
_diffrn_standards_decay_%        'no decay, variation 0.2'
_diffrn_standards_interval_time  180
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    .076
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            violet
_exptl_crystal_density_diffrn    1.349
_exptl_crystal_density_method    'Not Measured'
_exptl_crystal_description       needle-block
_exptl_crystal_F_000             292
_exptl_crystal_size_max          .10
_exptl_crystal_size_mid          .08
_exptl_crystal_size_min          .08
_refine_diff_density_max         .140
_refine_diff_density_min         -.212
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   .943
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     199
_refine_ls_number_reflns         2684
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      .943
_refine_ls_R_factor_all          .2265
_refine_ls_R_factor_gt           .0685
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0608P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .1785
_reflns_number_gt                843
_reflns_number_total             2684
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1477.cif
_cod_data_source_block           Iat293K
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_database_code               2012157