Neutron diffraction investigations of l- and d-alanine at different temperatures: the search for structural evidence for parity violation
Wilson, Chick C.; Myles, Dean; Ghosh, Minakshi; Johnson, Louise N.; Wang, Wenging; New Journal of Chemistry 29 (2005) 1318–; doi:10.1039/b419295h

data_7050083
_publ_section_title
;
 Neutron diffraction investigations of l- and d-alanine at different
 temperatures: the search for structural evidence for parity violation
;
_journal_issue                   10
_journal_name_full               'New Journal of Chemistry'
_journal_page_first              1318
_journal_paper_doi               10.1039/b419295h
_journal_volume                  29
_journal_year                    2005
_chemical_formula_sum            'C3 H7 N O2'
_chemical_formula_weight         89.00
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.000
_cell_angle_beta                 90.000
_cell_angle_gamma                90.000
_cell_formula_units_Z            4
_cell_length_a                   5.942(3)
_cell_length_b                   12.261(5)
_cell_length_c                   5.7850(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    60(1)
_cell_volume                     421.5(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      60(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  0.069
_diffrn_reflns_av_sigmaI/netI    0.0208
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       30
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4081
_exptl_absorpt_coefficient_mu    '2.610, at 1 Angstrom'
_exptl_absorpt_correction_T_max  0.64
_exptl_absorpt_correction_T_min  0.26
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
;
The linear absorption coefficient is wavelength dependent
and it is calculated as:
mu = 1.34 + 1.27 * lambda [cm^-1]
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.403
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregular prism'
_exptl_crystal_F_000             5.87
_exptl_crystal_size_max          3.0
_exptl_crystal_size_mid          3.0
_exptl_crystal_size_min          2.0
_refine_diff_density_max         0.440
_refine_diff_density_min         -0.366
_refine_diff_density_rms         0.071
_refine_ls_extinction_coef       0.042
_refine_ls_extinction_method     'Becker-Coppens Lorentzian model'
_refine_ls_goodness_of_fit_ref   1.941
_refine_ls_hydrogen_treatment    'mixed refall'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     119
_refine_ls_number_reflns         1968
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.941
_refine_ls_R_factor_all          0.0799
_refine_ls_R_factor_gt           0.0799
_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^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2012
_refine_ls_wR_factor_ref         0.2012
_reflns_number_gt                1968
_reflns_number_total             1968
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b419295h.txt
_cod_data_source_block           dala60kinv
_cod_depositor_comments
;
 Adding quotes around the values of the _atom_type_scat_source data item.

 Antanas Vaitkus,
 2018-08-07
;
_cod_original_cell_volume        421.47
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               7050083