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_1552796
_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            'C19 H36 N2 O5'
_chemical_formula_weight         372.50
_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   mixed
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.2149(6)
_cell_length_b                   15.0953(11)
_cell_length_c                   27.017(3)
_cell_measurement_reflns_used    4902
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.6
_cell_measurement_theta_min      2.6
_cell_volume                     2126.8(4)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Xcalibur, Eos, Nova'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1176
_diffrn_reflns_av_unetI/netI     0.1497
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -35
_diffrn_reflns_number            17022
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.561
_diffrn_reflns_theta_min         2.634
_diffrn_source                   'Mova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.14040
_exptl_absorpt_correction_type   multi-scan
_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    1.163
_exptl_crystal_description       needle
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.550
_exptl_crystal_size_mid          0.091
_exptl_crystal_size_min          0.068
_refine_diff_density_max         0.409
_refine_diff_density_min         -0.441
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details
;
 Flack x determined using 674 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   2.0(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.077
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     278
_refine_ls_number_reflns         4902
_refine_ls_number_restraints     91
_refine_ls_restrained_S_all      1.071
_refine_ls_R_factor_all          0.1512
_refine_ls_R_factor_gt           0.0945
_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^)+(0.0481P)^2^+0.7159P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1555
_refine_ls_wR_factor_ref         0.1878
_reflns_Friedel_coverage         0.719
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.995
_reflns_number_gt                2992
_reflns_number_total             4902
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jp7b10939_si_005.cif
_cod_data_source_block           shelx
_cod_database_code               1552796
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.956
_shelx_estimated_absorpt_t_max   0.994
_shelx_res_checksum              11369
_shelx_hkl_checksum              61825