Syn vs Anti Carboxylic Acids in Hybrid Peptides: Experimental and Theoretical Charge Density and Chemical Bonding Analysis.
Pal, Rumpa; Reddy, M. B. Madhusudana; Dinesh, B.; Venkatesha, Manjunath A.; Grabowsky, Simon; Jelsch, Christian; Guru Row, Tayur N.; The journal of physical chemistry. A 122 (2018) 3665–3679; doi:10.1021/acs.jpca.7b10939

data_1552795
_publ_section_title
;
 Syn vs Anti Carboxylic Acids in Hybrid Peptides: Experimental and
 Theoretical Charge Density and Chemical Bonding Analysis.
;
_journal_issue                   14
_journal_name_full               'The journal of physical chemistry. A'
_journal_page_first              3665
_journal_page_last               3679
_journal_paper_doi               10.1021/acs.jpca.7b10939
_journal_volume                  122
_journal_year                    2018
_chemical_absolute_configuration syn
_chemical_formula_sum            'C32 H62 N4 O8'
_chemical_formula_weight         630.85
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 106.622(11)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   10.3122(10)
_cell_length_b                   10.9803(19)
_cell_length_c                   16.8121(19)
_cell_measurement_reflns_used    6938
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      25.0
_cell_measurement_theta_min      2.5
_cell_volume                     1824.1(4)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Xcalibur, Eos, Nova'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0718
_diffrn_reflns_av_unetI/netI     0.1990
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            6938
_diffrn_reflns_point_group_measured_fraction_full 0.810
_diffrn_reflns_point_group_measured_fraction_max 0.810
_diffrn_reflns_theta_full        25.027
_diffrn_reflns_theta_max         25.027
_diffrn_reflns_theta_min         2.529
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.48846
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.149
_exptl_crystal_description       needle
_exptl_crystal_F_000             692
_exptl_crystal_size_max          0.576
_exptl_crystal_size_mid          0.113
_exptl_crystal_size_min          0.039
_refine_diff_density_max         0.289
_refine_diff_density_min         -0.304
_refine_diff_density_rms         0.062
_refine_ls_abs_structure_details
;
 Flack x determined using 377 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.9(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.020
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     410
_refine_ls_number_reflns         5201
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.020
_refine_ls_R_factor_all          0.1827
_refine_ls_R_factor_gt           0.0972
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0567P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1744
_refine_ls_wR_factor_ref         0.2354
_reflns_Friedel_coverage         0.535
_reflns_Friedel_fraction_full    0.599
_reflns_Friedel_fraction_max     0.599
_reflns_number_gt                2386
_reflns_number_total             5201
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jp7b10939_si_003.cif
_cod_data_source_block           shelx
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               1552795
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.954
_shelx_estimated_absorpt_t_max   0.997
_shelx_res_checksum              55201
_shelx_hkl_checksum              4163