Methyl group librations in sterically hindered dimethylnaphthalene molecules: neutron diffraction studies of 1,8-dimethylnaphthalene between 50 and 200 K
Wilson, Chick C.; Nowell, Harriott; New Journal of Chemistry 24 (2000) 1063–; doi:10.1039/b004123h

data_7051324
_publ_section_title
;
 Methyl group librations in sterically hindered dimethylnaphthalene
 molecules: neutron diffraction studies of 1,8-dimethylnaphthalene
 between 50 and 200 K
;
_journal_issue                   12
_journal_name_full               'New Journal of Chemistry'
_journal_page_first              1063
_journal_paper_doi               10.1039/b004123h
_journal_volume                  24
_journal_year                    2000
_chemical_formula_sum            'C12 H12'
_chemical_formula_weight         156.2
_chemical_name_common            1,8-dimethylnaphthalene
_chemical_name_systematic
;
1,8-dimethylnaphthalene                                                         
;
_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'
_cell_angle_alpha                90.00
_cell_angle_beta                 124.39(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.678(2)
_cell_length_b                   6.917(2)
_cell_length_c                   16.141(4)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    100(1)
_cell_volume                     891.7(4)
_computing_molecular_graphics    ' ORTEP (Johnson, 1994)'
_computing_structure_refinement  ' SHELXL-93 (Sheldrick, 1993)'
_diffrn_ambient_temperature      100(1)
_diffrn_measurement_device       SXD
_diffrn_measurement_method       'time-of-flight LAUE diffraction'
_diffrn_radiation_monochromator  none
_diffrn_radiation_probe          neutron
_diffrn_radiation_source         'ISIS spallation source'
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.5-5.0
_diffrn_reflns_av_R_equivalents  0.062
_diffrn_reflns_av_sigmaI/netI    0.0446
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            2788
_exptl_absorpt_coefficient_mu    '2.080, at 1 Angstrom'
_exptl_absorpt_correction_T_max  0.84
_exptl_absorpt_correction_T_min  0.41
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
;
The linear absorption coefficient is wavelength dependent
 and it is calculated as: 
          mu = 1.08 + 1.00 * lambda  [cm^-1]
;
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.162
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'thick plate'
_exptl_crystal_F_000             13.97
_exptl_crystal_size_max          2.5
_exptl_crystal_size_mid          2.5
_exptl_crystal_size_min          1.0
_refine_diff_density_max         0.128
_refine_diff_density_min         -0.138
_refine_diff_density_rms         0.028
_refine_ls_extinction_coef       0.130
_refine_ls_extinction_method     'Becker-Coppens Lorentzian model'
_refine_ls_goodness_of_fit_ref   1.190
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         1297
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.190
_refine_ls_R_factor_all          0.0933
_refine_ls_R_factor_gt           0.0933
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1216P)^2^+0.3666P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2226
_refine_ls_wR_factor_ref         0.2226
_reflns_number_gt                1297
_reflns_number_total             1297
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b004123h.txt
_cod_data_source_block           18dmn100K
_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 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.1216P)^2^+0.3666P] 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^)+(0.1216P)^2^+0.3666P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      P21/c
_cod_database_code               7051324