Direct determination of the hydrogen bonding arrangement in anhydrous β-chitin by neutron fiber diffraction.
Sawada, Daisuke; Nishiyama, Yoshiharu; Langan, Paul; Forsyth, V. Trevor; Kimura, Satoshi; Wada, Masahisa; Biomacromolecules 13 (2012) 288–291; doi:10.1021/bm201512t

data_1508508
_publ_section_title
;
 Direct determination of the hydrogen bonding arrangement in anhydrous
 \b-chitin by neutron fiber diffraction.
;
_journal_issue                   1
_journal_name_full               Biomacromolecules
_journal_page_first              288
_journal_page_last               291
_journal_paper_doi               10.1021/bm201512t
_journal_volume                  13
_journal_year                    2012
_chemical_formula_sum            'C8 H10 D3 N O5'
_chemical_formula_weight         206.14
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2c'
_symmetry_space_group_name_H-M   'P 1 1 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2011-11-25 # Formatted by publCIF
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                97.16(5)
_cell_formula_units_Z            2
_cell_length_a                   4.8190(10)
_cell_length_b                   9.239(2)
_cell_length_c                   10.384(2)
_cell_measurement_temperature    293(2)
_cell_volume                     458.72(17)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.381
_diffrn_measured_fraction_theta_max 0.381
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          neutron
_diffrn_radiation_source         neutron
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     1.45580
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.1205
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       0
_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            145
_diffrn_reflns_theta_full        40.89
_diffrn_reflns_theta_max         40.89
_diffrn_reflns_theta_min         6.08
_exptl_absorpt_coefficient_mu    0.352
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.492
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'uniaxially oriented fibers'
_exptl_crystal_F_000             148
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.004
_refine_diff_density_max         0.926
_refine_diff_density_min         -0.799
_refine_diff_density_rms         0.274
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   10(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   2.800
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     13
_refine_ls_number_reflns         145
_refine_ls_number_restraints     26
_refine_ls_restrained_S_all      3.596
_refine_ls_R_factor_all          0.4685
_refine_ls_R_factor_gt           0.2566
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.5303
_refine_ls_wR_factor_ref         0.6239
_reflns_number_gt                93
_reflns_number_total             145
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bm201512t_si_001.cif
_cod_data_source_block           manhyd
_cod_original_cell_volume        458.72(16)
_cod_database_code               1508508