Fast event-based electron counting for small-molecule structure determination by MicroED.
Vlahakis, Niko; Qu, Songrong; Richards, Logan S.; Moraes, Lygia Silva de; Cascio, Duilio; Nelson, Hosea M.; Rodriguez, Jose A.; Acta crystallographica. Section C, Structural chemistry 81 (2025) 116–130; doi:10.1107/S2053229624012300

data_2312763
_publ_section_title
;
 Fast event-based electron counting for small-molecule structure
 determination by MicroED.
;
_journal_coeditor_code           YP3239
_journal_issue                   'Pt 3'
_journal_name_full
'Acta crystallographica. Section C, Structural chemistry'
_journal_page_first              116
_journal_page_last               130
_journal_paper_doi               10.1107/S2053229624012300
_journal_volume                  81
_journal_year                    2025
_chemical_absolute_configuration rm
_chemical_formula_iupac          'C10 H16 N2 O3 S1'
_chemical_formula_moiety         'C10 H16 N2 O3 S1'
_chemical_formula_sum            'C10 H16 N2 O3 S'
_chemical_formula_weight         244.31
_chemical_name_common            biotin
_chemical_name_systematic
;
5-[(3a<i>S</i>,4<i>S</i>,6a<i>R</i>)-2-Oxohexahydro-1<i>H</i>-\
thieno[3,4-<i>d</i>]imidazol-4-yl]pentanoic acid
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2019/3
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.170(2)
_cell_length_b                   10.1100(19)
_cell_length_c                   20.710(3)
_cell_measurement_reflns_used    4422
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      0.900
_cell_measurement_theta_min      0.099
_cell_volume                     1082.5(5)
_computing_structure_refinement
;
SHELXL2019 (Sheldrick, 2015<i>b</i>)
;
_computing_structure_solution
;
SHELXT2018 (Sheldrick, 2015<i>a</i>)
;
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.856
_diffrn_measured_fraction_theta_max 0.847
_diffrn_measurement_device_type  TEM
_diffrn_measurement_method       'continuous rotation 3D ED'
_diffrn_radiation_type           electron
_diffrn_radiation_wavelength     0.0251
_diffrn_reflns_av_R_equivalents  0.1409
_diffrn_reflns_av_unetI/netI     0.1667
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            4422
_diffrn_reflns_theta_full        0.863
_diffrn_reflns_theta_max         0.900
_diffrn_reflns_theta_min         0.099
_diffrn_source                   FEG
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.000
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.499
_exptl_crystal_description       needle
_exptl_crystal_F_000             196
_exptl_crystal_size_max          0.010
_exptl_crystal_size_mid          0.0005
_exptl_crystal_size_min          0.00015
_refine_diff_density_max         0.232
_refine_diff_density_min         -0.205
_refine_ls_abs_structure_details
;
 All f" are zero, so absolute structure could not be determined
;
_refine_ls_extinction_coef       1047E1(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method
;
SHELXL2019 (Sheldrick, 2015<i>b</i>)
;
_refine_ls_goodness_of_fit_ref   1.325
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     148
_refine_ls_number_reflns         1926
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.325
_refine_ls_R_factor_all          0.1856
_refine_ls_R_factor_gt           0.1586
_refine_ls_shift/su_max          0.018
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.2000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3832
_refine_ls_wR_factor_ref         0.4094
_reflns_number_gt                1397
_reflns_number_total             1926
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            yp3239.cif
_cod_data_source_block           a
_cod_depositor_comments
'Adding full bibliography for 2312763--2312764.cif.'
_cod_original_formula_sum        'C10 H16 N2 O3 S1'
_cod_database_code               2312763
_shelx_hkl_checksum              95204
_shelx_res_checksum              5829