Low-temperature (110K) single-crystal neutron diffraction study of (±)-camphoric anhydride
Kgomo, Ditebogo B.; Levendis, Demetrius C.; Gukasov, Arsen; Cousson, Alain; Schöning, Ludwig F. R.; Venter, Andrew M.; Acta Crystallographica Section E 61 (2005) o1141–o1143; doi:10.1107/S1600536805008950

data_2205478
_publ_section_title
;
 Low-temperature (110K) single-crystal neutron diffraction study of
 (+-)-camphoric anhydride
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1141
_journal_page_last               o1143
_journal_paper_doi               10.1107/S1600536805008950
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C10 H14 O3'
_chemical_formula_moiety         'C10 H14 O3'
_chemical_formula_sum            'C10 H14 O3'
_chemical_formula_weight         182.22
_chemical_name_systematic
;
(+-)-1,8,8-Trimethyl-3-oxabicyclo[3.2.1]octane-2,4-dione
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   difmap
_audit_creation_method           CRYSTALS_ver_12.39
_cell_angle_alpha                90
_cell_angle_beta                 92.179(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.5001(8)
_cell_length_b                   11.5624(14)
_cell_length_c                   12.7093(15)
_cell_measurement_reflns_used    15
_cell_measurement_temperature    110
_cell_measurement_theta_max      22
_cell_measurement_theta_min      16
_cell_volume                     954.5(2)
_computing_cell_refinement       DIF4N
_computing_data_collection
'DIF4N (modified Linux version of DIF4; Stoe & Cie, 1991)'
_computing_data_reduction
'PRON98 (modified version of REDU4; Stoe & Cie, 1990; Meven, Year?)'
_computing_molecular_graphics
'ORTEP-3 for Windows (Farrugia, 1997) and CAMERON (Watkin <i>et al.</i>, 1996)'
_computing_publication_material  CRYSTALS
_computing_structure_refinement  'CRYSTALS (Betteridge <i>et al.</i>, 2003)'
_computing_structure_solution
'a previous X-ray study gave position parameters for heavy atoms (Reference?)'
_diffrn_ambient_temperature      110
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type
;
5C2 four-circle (Orph\'ee reactor, Saclay, France)
;
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  Cu_(220)
_diffrn_radiation_probe          neutron
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.83300
_diffrn_reflns_av_R_equivalents  0.047
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       1
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4137
_diffrn_reflns_theta_full        39.506
_diffrn_reflns_theta_max         39.506
_diffrn_reflns_theta_min         2.792
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  450
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.268
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       prism
_exptl_crystal_F_000             128
_exptl_crystal_size_max          5.00
_exptl_crystal_size_mid          4.00
_exptl_crystal_size_min          3.00
_refine_diff_density_max         0.12
_refine_diff_density_min         -0.14
_refine_ls_extinction_coef       3.4(8)
_refine_ls_extinction_method     'Larson (1970), eq. 22'
_refine_ls_goodness_of_fit_ref   1.1006
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         1594
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0844
_refine_ls_R_factor_gt           0.0590
_refine_ls_shift/su_max          0.000154
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Chebychev polynomial, (Watkin, 1994; Prince, 1982) W =
[weight][1-(\DF/6\sF)^2^]^2^ where  [weight] = 1.0/[A~0~T~0~(x)+A~1~T~1~(x)
... +A~n-1~T~n-1~(x)] where x = Fcalc/Fmax and A~i~ are the Chebychev
coefficients  listed below: 0.703 -0.458 0.556 -0.177 0.795E-01
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0627
_refine_ls_wR_factor_gt          0.0566
_refine_ls_wR_factor_ref         0.0566
_reflns_number_gt                1594
_reflns_number_total             3553
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            dn6207.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2205478
_cod_database_fobs_code          2205478