Aggregation modes in sheets formed by protected beta-amino acids and beta-peptides.
Sengupta, Anindita; Roy, Rituparna S.; Sabareesh, Varatharajan; Shamala, Narayanaswamy; Balaram, Padmanabhan; Organic & biomolecular chemistry 4 (2006) 1166–1173; doi:10.1039/b516088j

data_7150419
_publ_section_title
;
 Aggregation modes in sheets formed by protected beta-amino acids and
 beta-peptides.
;
_journal_issue                   6
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1166
_journal_page_last               1173
_journal_paper_doi               10.1039/b516088j
_journal_volume                  4
_journal_year                    2006
_chemical_formula_sum            'C18 H34 N2 O5'
_chemical_formula_weight         358.47
_chemical_name_common            Boc-betaVal-betaDVal-OMe
_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   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.170(4)
_cell_length_b                   10.860(8)
_cell_length_c                   37.30(3)
_cell_measurement_temperature    293(2)
_cell_volume                     2094(3)
_computing_data_collection       SMART
_computing_data_reduction        SAINT
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'BRUKER AXS SMART APEX CCD with Mo source'
_diffrn_measurement_method       'omega scan'
_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  0.0752
_diffrn_reflns_av_sigmaI/netI    0.0465
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            13067
_diffrn_reflns_theta_full        23.25
_diffrn_reflns_theta_max         23.25
_diffrn_reflns_theta_min         1.09
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.137
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             784
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.06
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.284
_refine_diff_density_min         -0.261
_refine_diff_density_rms         0.096
_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   1.273
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     226
_refine_ls_number_reflns         1807
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.273
_refine_ls_R_factor_all          0.1091
_refine_ls_R_factor_gt           0.0787
_refine_ls_shift/su_max          0.016
_refine_ls_shift/su_mean         0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0840P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1588
_refine_ls_wR_factor_ref         0.1809
_reflns_number_gt                1393
_reflns_number_total             1807
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b516088j.txt
_cod_data_source_block           lvdv
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from
2010-06-29.

'_exptl_absorpt_correction_type' value 'None' changed to
'none' according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7150419