X-ray Structure of Anhydrous β-Chitin at 1 Å Resolution
Nishiyama, Yoshiharu; Noishiki, Yasutomo; Wada, Masahisa; Macromolecules 44 (2011) 950–; doi:10.1021/ma102240r

data_1501776
_publ_section_title
;
 X-ray Structure of Anhydrous \b-Chitin at 1 \%A Resolution
;
_journal_issue                   4
_journal_name_full               Macromolecules
_journal_page_first              950
_journal_paper_doi               10.1021/ma102240r
_journal_volume                  44
_journal_year                    2011
_chemical_formula_sum            'C8 H13 N O5'
_chemical_formula_weight         203.19
_chemical_name_common            chitin
_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
;
2010-09-14 # 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_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      10
_cell_measurement_theta_min      3
_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_detector_area_resol_mean 100
_diffrn_measured_fraction_theta_full 0.424
_diffrn_measured_fraction_theta_max 0.424
_diffrn_measurement_device_type  'image plate'
_diffrn_measurement_method       'two dimensional peak fitting'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         synchrotron
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.72930
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    2.2052
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            216
_diffrn_reflns_theta_full        21.35
_diffrn_reflns_theta_max         21.35
_diffrn_reflns_theta_min         2.28
_exptl_absorpt_coefficient_mu    0.123
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.471
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'uniaxially oriented whiskers'
_exptl_crystal_F_000             216
_exptl_crystal_size_max          0.01
_exptl_crystal_size_mid          0.0001
_exptl_crystal_size_min          0.00003
_refine_diff_density_max         0.127
_refine_diff_density_min         -0.103
_refine_diff_density_rms         0.037
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.983
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     130
_refine_ls_number_reflns         216
_refine_ls_number_restraints     283
_refine_ls_restrained_S_all      0.501
_refine_ls_R_factor_all          0.1431
_refine_ls_R_factor_gt           0.0701
_refine_ls_shift/su_max          0.120
_refine_ls_shift/su_mean         0.010
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1785P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1723
_refine_ls_wR_factor_ref         0.2099
_reflns_number_gt                105
_reflns_number_total             216
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ma102240r_si_001.cif
_cod_data_source_block           betachitin
_cod_original_cell_volume        458.72(16)
_cod_database_code               1501776