Citraconic Acid
Batchelor, Elaine; Jones, William; Acta Crystallographica Section C 54 (1998) 238–240; doi:10.1107/S0108270197014224

data_2007015
_publ_section_title
;
 Citraconic Acid
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              238
_journal_page_last               240
_journal_paper_doi               10.1107/S0108270197014224
_journal_volume                  54
_journal_year                    1998
_chemical_formula_moiety         'C5 H6 O4'
_chemical_formula_sum            'C5 H6 O4'
_chemical_formula_weight         130.10
_chemical_melting_point          .88E-94
_chemical_name_common            'Citraconic acid'
_chemical_name_systematic
;
 2-methyl-2-butenedioic acid
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_audit_creation_method           shelxl
_cell_angle_alpha                88.860(9)
_cell_angle_beta                 71.254(8)
_cell_angle_gamma                81.261(9)
_cell_formula_units_Z            2
_cell_length_a                   5.4239(5)
_cell_length_b                   7.1863(9)
_cell_length_c                   8.1732(8)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      20
_cell_measurement_theta_min      15
_cell_volume                     298.03(6)
_computing_cell_refinement       'SETANG CAD4 Software'
_computing_data_collection       'CAD4 Software (Enraf-Nonius, 1989)'
_computing_data_reduction
'TEXSAN (Molecular Structure Corporation, 1995)'
_computing_molecular_graphics    TEXSAN
_computing_publication_material  SHELXL93
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      295(2)
_diffrn_measurement_device       'Enraf Nonius CAD4'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0392
_diffrn_reflns_av_sigmaI/netI    0.0448
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1134
_diffrn_reflns_theta_max         24.95
_diffrn_reflns_theta_min         2.63
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  3600
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.128
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.450
_exptl_crystal_description       rod
_exptl_crystal_F_000             136
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.219
_refine_diff_density_min         -0.211
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   0.973
_refine_ls_goodness_of_fit_obs   1.003
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     93
_refine_ls_number_reflns         1054
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.973
_refine_ls_restrained_S_obs      1.003
_refine_ls_R_factor_all          0.0951
_refine_ls_R_factor_obs          .0489
_refine_ls_shift/esd_max         0.011
_refine_ls_shift/esd_mean        0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0241P)^2^+0.6395P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1574
_refine_ls_wR_factor_obs         .1277
_reflns_number_observed          685
_reflns_number_total             1054
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ha1205.cif
_cod_data_source_block           i
_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 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0241P)^2^+0.6395P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.0241P)^2^+0.6395P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        298.03(5)
_cod_database_code               2007015