Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure
Oswald, Iain D. H.; Urquhart, Andrew J.; CrystEngComm 13 (2011) 4503–; doi:10.1039/c1ce05295k

data_7206294
_publ_section_title
;
 Polymorphism and polymerisation of acrylic and methacrylic acid at
 high pressure
;
_journal_issue                   14
_journal_name_full               CrystEngComm
_journal_page_first              4503
_journal_paper_doi               10.1039/c1ce05295k
_journal_volume                  13
_journal_year                    2011
_chemical_formula_moiety         'C3 H4 O2'
_chemical_formula_sum            'C3 H4 O2'
_chemical_formula_weight         72.06
_space_group_IT_number           72
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-I 2 2c'
_symmetry_space_group_name_H-M   'I b a m'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             11-02-15
_audit_creation_method           CRYSTALS_ver_14.11
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   9.959(3)
_cell_length_b                   11.667(3)
_cell_length_c                   6.3044(11)
_cell_measurement_reflns_used    400
_cell_measurement_temperature    293
_cell_measurement_theta_max      18
_cell_measurement_theta_min      5
_cell_volume                     732.5(3)
_computing_cell_refinement       'Apex2 (Bruker AXS, 2006)'
_computing_data_collection       'Apex2 (Bruker AXS, 2006)'
_computing_data_reduction        'Apex2 (Bruker AXS, 2006)'
_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    'SHELXS 86 (Sheldrick, 1986)'
_diffrn_ambient_pressure         400000
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_full 0.763
_diffrn_measured_fraction_theta_max 0.680
_diffrn_measurement_device       Area
_diffrn_measurement_device_type  'Bruker Kappa Apex2'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.034
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            1615
_diffrn_reflns_theta_full        17.451
_diffrn_reflns_theta_max         23.268
_diffrn_reflns_theta_min         5.183
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.111
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.82
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Siemens, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.307
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             304
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.300
_exptl_crystal_size_min          0.050
_refine_diff_density_max         0.21
_refine_diff_density_min         -0.28
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0324
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     34
_refine_ls_number_reflns         201
_refine_ls_number_restraints     31
_refine_ls_R_factor_all          0.0761
_refine_ls_R_factor_gt           0.0427
_refine_ls_shift/su_max          0.0000803
_refine_ls_shift/su_mean         0.0000163
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
Method= Modified Sheldrick
w=1/[\s^2^(F^2^) + ( 0.07P)^2^ + 0.02P]
,where P=(max(Fo^2^,0) + 2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1187
_refine_ls_wR_factor_gt          0.0931
_refine_ls_wR_factor_ref         0.1187
_reflns_limit_h_max              9
_reflns_limit_h_min              0
_reflns_limit_k_max              11
_reflns_limit_k_min              0
_reflns_limit_l_max              6
_reflns_limit_l_min              0
_reflns_number_gt                113
_reflns_number_total             201
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   0.00
_oxford_diffrn_Wilson_scale      0.00
_oxford_refine_ls_r_factor_ref   0.0761
_oxford_refine_ls_scale          0.1885(7)
_oxford_reflns_number_all        201
_oxford_reflns_threshold_expression_ref I>-10.0\s(I)
_cod_data_source_file            c1ce05295k.txt
_cod_data_source_block           1
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' 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_original_sg_symbol_H-M      'I b a m '
_cod_database_code               7206294
_iucr_refine_instruction_details_constraints
;
BLOCK SCALE X'S, U'S
RIDE O ( 1,X'S) H ( 1,X'S)
RIDE C ( 2,X'S) H ( 2,X'S)
RIDE C ( 3,X'S) H ( 3,X'S) H ( 4,X'S)
END
;
_iucr_refine_instruction_details_restraints
;
NO
REM HREST START (DO NOT REMOVE THIS LINE)
REM HREST END (DO NOT REMOVE THIS LINE)
REM DELU START (DO NOT REMOVE THIS LINE)
VIBR .0, 0.00200 = O(1) TO C(1)
VIBR .0, 0.00200 = O(2) TO C(1)
VIBR .0, 0.00200 = C(1) TO C(2)
VIBR .0, 0.00500 = O(2) TO O(1)
VIBR .0, 0.00500 = C(2) TO O(1)
VIBR .0, 0.00500 = C(2) TO O(2)
VIBR .0, 0.00200 = C(2) TO C(3)
VIBR .0, 0.00500 = C(3) TO C(1)
REM DELU END (DO NOT REMOVE THIS LINE)
REM THERMSIM START (DO NOT REMOVE THIS LINE)
U(IJ) .0, 0.08000 = O(1) TO C(1)
U(IJ) .0, 0.08000 = O(2) TO C(1)
U(IJ) .0, 0.04000 = C(1) TO C(2)
U(IJ) .0, 0.08000 = C(2) TO C(3)
REM THERMSIM END (DO NOT REMOVE THIS LINE)
END
;