An exploration of the polymorphism of piracetam using high pressure
Fabbiani, Francesca P. A.; Allan, David R.; Parsons, Simon; Pulham, Colin R.; CrystEngComm 7 (2005) 179–; doi:10.1039/b418976k

data_7203723
_publ_section_title
;
 An exploration of the polymorphism of piracetam using high pressure
;
_journal_issue                   29
_journal_name_full               CrystEngComm
_journal_page_first              179
_journal_paper_doi               10.1039/b418976k
_journal_volume                  7
_journal_year                    2005
_chemical_formula_moiety         'C6 H10 N2 O2'
_chemical_formula_sum            'C6 H10 N2 O2'
_chemical_formula_weight         142.16
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             04-11-09
_audit_creation_method           CRYSTALS_ver_12.39
_cell_angle_alpha                90
_cell_angle_beta                 104.93(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.9537(11)
_cell_length_b                   5.4541(6)
_cell_length_c                   13.610(4)
_cell_measurement_reflns_used    379
_cell_measurement_temperature    293
_cell_measurement_theta_max      26
_cell_measurement_theta_min      4
_cell_volume                     642.2(2)
_computing_cell_refinement       'SAINT (Siemens ,1995)'
_computing_data_collection       'SMART (Siemens, 1993)'
_computing_data_reduction        'SAINT (Siemens ,1995)'
_computing_molecular_graphics    'CAMERON (Watkin et al 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al 2003)'
_computing_structure_solution    'SIR92 (Altomare et al, 1994)'
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_full 0.376
_diffrn_measured_fraction_theta_max 0.344
_diffrn_measurement_device_type  'Bruker SMART'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0784
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            3718
_diffrn_reflns_theta_full        25.162
_diffrn_reflns_theta_max         26.768
_diffrn_reflns_theta_min         4.045
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.112
_exptl_absorpt_correction_T_max  1.00
_exptl_absorpt_correction_T_min  0.61
_exptl_absorpt_correction_type   'Empirical & multi-scan'
_exptl_absorpt_process_details
;
SHADE (Parsons, 2004)
SADABS (Siemens, 1996)
The following data are from Sadabs:
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.470
_exptl_crystal_description       block
_exptl_crystal_F_000             304
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.20
_refine_diff_density_min         -0.24
_refine_ls_extinction_coef       57(17)
_refine_ls_extinction_method     'Larson 1970 Crystallographic Computing eq 22'
_refine_ls_goodness_of_fit_ref   1.0911
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     92
_refine_ls_number_reflns         457
_refine_ls_number_restraints     83
_refine_ls_R_factor_all          0.0724
_refine_ls_R_factor_gt           0.0526
_refine_ls_shift/su_max          0.000135
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
p=P(6)*max(Fo^2^,0) + (1-P(6))Fc^2^
Method = SHELXL 97 (Sheldrick, 1997)
W = 1. / [Sigma^2^(F*)+(P(1)p)^2^+P(2)p+P(4)+P(5)Sin(theta) ]
P(i) are:
0.247E-01 0.610 0.00 0.00 0.00 0.333
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1026
_refine_ls_wR_factor_gt          0.0957
_refine_ls_wR_factor_ref         0.1026
_reflns_limit_h_max              10
_reflns_limit_h_min              -11
_reflns_limit_k_max              6
_reflns_limit_k_min              0
_reflns_limit_l_max              9
_reflns_limit_l_min              0
_reflns_number_gt                359
_reflns_number_total             470
_reflns_threshold_expression     I>2.00u(I)
_oxford_diffrn_Wilson_B_factor   1.57
_oxford_diffrn_Wilson_scale      79.84
_oxford_refine_ls_scale          0.436(2)
_oxford_structure_analysis_title '5678 in P2(1)/c'
_cod_data_source_file            b418976k.txt
_cod_data_source_block           CRYSTALS_cif_2
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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 
;
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               7203723