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_7206297
_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         'C4 H6 O2'
_chemical_formula_sum            'C4 H6 O2'
_chemical_formula_weight         86.09
_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             11-02-15
_audit_creation_method           CRYSTALS_ver_14.11
_cell_angle_alpha                90
_cell_angle_beta                 91.24(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   3.8808(11)
_cell_length_b                   10.616(6)
_cell_length_c                   11.718(4)
_cell_measurement_reflns_used    275
_cell_measurement_temperature    293
_cell_measurement_theta_max      19
_cell_measurement_theta_min      3
_cell_volume                     482.7(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         300000
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_full 0.618
_diffrn_measured_fraction_theta_max 0.501
_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       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            1966
_diffrn_reflns_theta_full        17.447
_diffrn_reflns_theta_max         23.263
_diffrn_reflns_theta_min         2.589
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.76
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Siemens, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.185
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             184
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.300
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.27
_refine_diff_density_min         -0.23
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0836
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     55
_refine_ls_number_reflns         350
_refine_ls_number_restraints     28
_refine_ls_R_factor_all          0.1155
_refine_ls_R_factor_gt           0.0590
_refine_ls_shift/su_max          0.0000630
_refine_ls_shift/su_mean         0.0000145
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
Method= Modified Sheldrick
w=1/[\s^2^(F^2^) + ( 0.03P)^2^ + 0.39P]
,where P=(max(Fo^2^,0) + 2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1354
_refine_ls_wR_factor_gt          0.1143
_refine_ls_wR_factor_ref         0.1354
_reflns_limit_h_max              4
_reflns_limit_h_min              -4
_reflns_limit_k_max              8
_reflns_limit_k_min              0
_reflns_limit_l_max              12
_reflns_limit_l_min              0
_reflns_number_gt                197
_reflns_number_total             350
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   4.95
_oxford_diffrn_Wilson_scale      2.09
_oxford_refine_ls_r_factor_ref   0.1155
_oxford_refine_ls_scale          1.066(17)
_oxford_reflns_number_all        350
_oxford_reflns_threshold_expression_ref I>-10.0\s(I)
_cod_data_source_file            c1ce05295k.txt
_cod_data_source_block           4
_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_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_cell_volume        482.6(3)
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               7206297
_iucr_refine_instruction_details_constraints
;
BLOCK SCALE X'S, U'S
RIDE C ( 4,X'S) H ( 5,X'S) H ( 7,X'S) H ( 6,X'S)
RIDE C ( 3,X'S) H ( 4,X'S) H ( 3,X'S)
RIDE O ( 1,X'S) H ( 1,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, 0.00100 = C(1) TO C(2)
VIBR .0, 0.00100 = C(2) TO C(3)
VIBR .0, 0.00100 = C(2) TO C(4)
VIBR .0, 0.00300 = C(3) TO C(1)
VIBR .0, 0.00300 = C(4) TO C(1)
VIBR .0, 0.00300 = C(4) TO C(3)
VIBR .0, 0.00100 = C(4) TO O(5)
VIBR .0, 0.00100 = C(4) TO O(6)
VIBR .0, 0.00300 = O(5) TO C(2)
VIBR .0, 0.00300 = O(6) TO C(2)
VIBR .0, 0.00300 = O(6) TO O(5)
REM DELU END (DO NOT REMOVE THIS LINE)
REM THERMSIM START (DO NOT REMOVE THIS LINE)
U(IJ) .0, 0.04000 = C(1) TO C(2)
U(IJ) .0, 0.04000 = C(2) TO C(3)
U(IJ) .0, 0.02000 = C(2) TO C(4)
U(IJ) .0, 0.04000 = C(4) TO O(5)
U(IJ) .0, 0.04000 = C(4) TO O(6)
REM THERMSIM END (DO NOT REMOVE THIS LINE)
DISTANCE 1.310000 , 0.010000 = C(1) TO O(1)
DISTANCE 1.230000 , 0.010000 = C(1) TO O(2)
DISTANCE 1.340000 , 0.010000 = C(2) TO C(3)
DISTANCE 1.470000 , 0.010000 = C(2) TO C(4)
END
;