Redetermined structure of β-<small>DL</small>-methionine at 105K: an example of the importance of freely refining the positions of the amino-group H atoms
Görbitz, Carl Henrik; Acta Crystallographica Section E 70 (2014) 341–343; doi:10.1107/S1600536814022223

data_2240074
_publ_section_title
;
 Redetermined structure of \b-<small>DL</small>-methionine at 105K: an
 example of the importance of freely refining the positions of the
 amino-group H atoms
;
_journal_coeditor_code           HB7289
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              341
_journal_page_last               343
_journal_paper_doi               10.1107/S1600536814022223
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'C5 H11 N O2 S'
_chemical_formula_moiety         'C5 H11 N O2 S'
_chemical_formula_sum            'C5 H11 N O2 S'
_chemical_formula_weight         149.21
_chemical_name_common            <i>DL</i>-methionine
_chemical_name_systematic
;
2-Amino-4-(methylsulfanyl)butanoic acid
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-I 2ya'
_space_group_name_H-M_alt        'I 1 2/a 1'
_symmetry_space_group_name_Hall  '-I 2ya'
_symmetry_space_group_name_H-M   'I 1 2/a 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014
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_cell_length_b                   4.6915(10)
_cell_length_c                   32.603(6)
_cell_measurement_reflns_used    1012
_cell_measurement_temperature    105(2)
_cell_measurement_theta_max      26.1
_cell_measurement_theta_min      2.6
_cell_volume                     1450.4(5)
_computing_cell_refinement
;
SAINT-NT (Bruker, 1999)
;
_computing_data_collection
;
SMART-NT (Bruker, 1999)
;
_computing_data_reduction
;
SAINT-NT (Bruker, 1999)
;
_computing_molecular_graphics
;
SHELXTL (Sheldrick, 2008)
;
_computing_publication_material
;
SHELXL2013 (Sheldrick, 2008)
;
_computing_structure_refinement
;
SHELXL2013 (Sheldrick, 2008)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      105(2)
_diffrn_detector_area_resol_mean 8.3
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.975
_diffrn_measurement_device_type  'Bruker SMART CCD area-detector'
_diffrn_measurement_method
'Sets of exposures each taken over 0.5\% \w rotation'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0230
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            6469
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.295
_diffrn_reflns_theta_min         2.603
_exptl_absorpt_coefficient_mu    0.376
_exptl_absorpt_correction_T_max  0.92
_exptl_absorpt_correction_T_min  0.85
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Bruker, 1998)
;
_exptl_crystal_colour            colourless
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_exptl_crystal_description       block
_exptl_crystal_F_000             640
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.349
_refine_diff_density_min         -0.229
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.259
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     91
_refine_ls_number_reflns         1436
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.259
_refine_ls_R_factor_all          0.0389
_refine_ls_R_factor_gt           0.0377
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0233P)^2^+2.4782P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0913
_refine_ls_wR_factor_ref         0.0918
_reflns_number_gt                1373
_reflns_number_total             1436
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            hb7289sup1.cif
_cod_data_source_block           I
_cod_database_code               2240074
_cod_database_fobs_code          2240074
_shelx_hkl_checksum              95601
_shelx_res_checksum              53088
_shelxl_version_number           2014-3