# Supplementary Information (SI) for ChemComm.
# This journal is © The Royal Society of Chemistry 2026

####################################################################### 
# 
# This file contains crystal structure data downloaded from the 
# Cambridge Structural Database (CSD) hosted by the Cambridge 
# Crystallographic Data Centre (CCDC).
# 
# Full information about CCDC data access policies and citation 
# guidelines are available at http://www.ccdc.cam.ac.uk/access/V1 
# 
# Audit and citation data items may have been added by the CCDC. 
# Please retain this information to preserve the provenance of 
# this file and to allow appropriate attribution of the data. 
# 
#######################################################################

data_dds_pyr_yn_chyral_0m_a
_database_code_depnum_ccdc_archive 'CCDC 2527132'
loop_
_audit_author_name
_audit_author_address
'Dipali Digangana Sahoo'
;Indian institute of technology, guwahati
India
;
_audit_update_record             
;
2026-01-30 deposited with the CCDC.	2026-03-18 downloaded from the CCDC.
;

_audit_creation_method           SHELXL-2019/3
_shelx_SHELXL_version_number     2019/3
_chemical_name_systematic        ?
_chemical_name_common            ?
_chemical_melting_point          ?
_chemical_formula_moiety         ?
_chemical_formula_sum            'C27 H21 N3'
_chemical_formula_weight         387.47

loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0034 0.0017 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
N N 0.0066 0.0034 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_H-M_alt        'P 21'
_space_group_name_Hall           'P 2yb'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;

loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, y+1/2, -z'

_cell_length_a                   10.9402(7)
_cell_length_b                   8.5319(5)
_cell_length_c                   11.4283(7)
_cell_angle_alpha                90
_cell_angle_beta                 97.701(2)
_cell_angle_gamma                90
_cell_volume                     1057.10(11)
_cell_formula_units_Z            2
_cell_measurement_temperature    297(2)
_cell_measurement_reflns_used    9972
_cell_measurement_theta_min      2.42
_cell_measurement_theta_max      24.91

_exptl_crystal_description       block
_exptl_crystal_colour            colourless
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_density_diffrn    1.217
_exptl_crystal_F_000             408
_exptl_transmission_factor_min   ?
_exptl_transmission_factor_max   ?
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_exptl_absorpt_coefficient_mu    0.071
_shelx_estimated_absorpt_T_min   ?
_shelx_estimated_absorpt_T_max   ?
_exptl_absorpt_correction_type   ?
_exptl_absorpt_correction_T_min  ?
_exptl_absorpt_correction_T_max  ?
_exptl_absorpt_process_details   ?
_exptl_absorpt_special_details   ?
_diffrn_ambient_temperature      297(2)
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_type           MoK\a
_diffrn_source                   ?
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       'φ and ω scans'
_diffrn_detector_area_resol_mean ?
_diffrn_reflns_number            25911
_diffrn_reflns_av_unetI/netI     0.0388
_diffrn_reflns_av_R_equivalents  0.0506
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_theta_min         1.878
_diffrn_reflns_theta_max         25.025
_diffrn_reflns_theta_full        25.025
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measured_fraction_theta_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_point_group_measured_fraction_full 0.998
_reflns_number_total             3726
_reflns_number_gt                2802
_reflns_threshold_expression     'I > 2σ(I)'
_reflns_Friedel_coverage         0.863
_reflns_Friedel_fraction_max     0.998
_reflns_Friedel_fraction_full    0.998

_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;

_computing_data_collection       'Bruker APEX2'
_computing_cell_refinement       'Bruker SAINT'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_computing_structure_refinement  'SHELXL-2019/2 (Sheldrick, 2019)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_refine_special_details          ?
_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.0374P)²+0.1394P] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
_atom_sites_solution_hydrogens   geom
_refine_ls_hydrogen_treatment    constr
_refine_ls_extinction_method     none
_refine_ls_extinction_coef       .
_refine_ls_abs_structure_details 
;
 Flack x determined using 1059 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -2.3(10)
_chemical_absolute_configuration R
_refine_ls_number_reflns         3726
_refine_ls_number_parameters     272
_refine_ls_number_restraints     1
_refine_ls_R_factor_all          0.0737
_refine_ls_R_factor_gt           0.0440
_refine_ls_wR_factor_ref         0.1010
_refine_ls_wR_factor_gt          0.0861
_refine_ls_goodness_of_fit_ref   1.112
_refine_ls_restrained_S_all      1.112
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
N1 N 0.5394(2) 0.5187(3) 0.3676(2) 0.0467(7) Uani 1 1 d . . . . .
N2 N 0.7174(2) 0.5177(3) 0.5200(2) 0.0444(7) Uani 1 1 d . . . . .
N3 N 0.7426(2) 0.5286(4) 0.6397(2) 0.0483(7) Uani 1 1 d . . . . .
C1 C 0.1965(3) 0.5341(5) 0.0420(3) 0.0483(8) Uani 1 1 d . . . . .
C2 C 0.0915(3) 0.6261(5) 0.0354(3) 0.0584(10) Uani 1 1 d . . . . .
H2 H 0.077630 0.686785 0.099900 0.070 Uiso 1 1 calc R U . . .
C3 C 0.0075(3) 0.6289(6) -0.0656(4) 0.0715(12) Uani 1 1 d . . . . .
H3 H -0.062701 0.691040 -0.068898 0.086 Uiso 1 1 calc R U . . .
C4 C 0.0271(4) 0.5404(7) -0.1608(3) 0.0757(12) Uani 1 1 d . . . . .
H4 H -0.029503 0.542875 -0.229163 0.091 Uiso 1 1 calc R U . . .
C5 C 0.1299(4) 0.4483(6) -0.1558(3) 0.0773(13) Uani 1 1 d . . . . .
H5 H 0.142230 0.387188 -0.220557 0.093 Uiso 1 1 calc R U . . .
C6 C 0.2163(3) 0.4451(5) -0.0547(3) 0.0684(11) Uani 1 1 d . . . . .
H6 H 0.286781 0.383480 -0.052176 0.082 Uiso 1 1 calc R U . . .
C7 C 0.2826(3) 0.5350(5) 0.1486(3) 0.0534(9) Uani 1 1 d . . . . .
C8 C 0.3540(3) 0.5390(5) 0.2368(3) 0.0524(9) Uani 1 1 d . . . . .
C9 C 0.4247(3) 0.5587(5) 0.3501(3) 0.0474(8) Uani 1 1 d . . . . .
C10 C 0.5945(3) 0.5423(4) 0.4833(3) 0.0413(7) Uani 1 1 d . . . . .
C11 C 0.5388(3) 0.5722(4) 0.5815(3) 0.0433(8) Uani 1 1 d . . . . .
C12 C 0.4013(3) 0.5914(4) 0.5690(3) 0.0507(10) Uani 1 1 d . . . . .
H12 H 0.381674 0.676012 0.621367 0.061 Uiso 1 1 calc R U . . .
C13 C 0.3589(3) 0.6401(5) 0.4408(3) 0.0591(10) Uani 1 1 d . . . . .
H13A H 0.271235 0.619297 0.422721 0.071 Uiso 1 1 calc R U . . .
H13B H 0.370646 0.752264 0.433968 0.071 Uiso 1 1 calc R U . . .
C14 C 0.6339(3) 0.5597(4) 0.6778(2) 0.0431(8) Uani 1 1 d . . . . .
C15 C 0.8147(3) 0.4802(4) 0.4533(3) 0.0457(9) Uani 1 1 d . . . . .
C16 C 0.8160(3) 0.5436(5) 0.3430(3) 0.0587(10) Uani 1 1 d . . . . .
H16 H 0.752708 0.609788 0.310834 0.070 Uiso 1 1 calc R U . . .
C17 C 0.9116(3) 0.5086(6) 0.2804(3) 0.0742(13) Uani 1 1 d . . . . .
H17 H 0.912337 0.549848 0.205188 0.089 Uiso 1 1 calc R U . . .
C18 C 1.0063(4) 0.4123(6) 0.3292(4) 0.0751(13) Uani 1 1 d . . . . .
H18 H 1.071289 0.389518 0.287232 0.090 Uiso 1 1 calc R U . . .
C19 C 1.0045(3) 0.3505(5) 0.4394(4) 0.0714(12) Uani 1 1 d . . . . .
H19 H 1.068454 0.285636 0.471995 0.086 Uiso 1 1 calc R U . . .
C20 C 0.9087(3) 0.3834(5) 0.5024(3) 0.0581(10) Uani 1 1 d . . . . .
H20 H 0.907574 0.340894 0.577159 0.070 Uiso 1 1 calc R U . . .
C21 C 0.3389(3) 0.4418(6) 0.6026(4) 0.0774(13) Uani 1 1 d . . . . .
H21A H 0.251355 0.458110 0.595494 0.116 Uiso 1 1 calc R U . . .
H21B H 0.369541 0.414416 0.682644 0.116 Uiso 1 1 calc R U . . .
H21C H 0.356274 0.358405 0.550904 0.116 Uiso 1 1 calc R U . . .
C22 C 0.6262(3) 0.5631(4) 0.8058(3) 0.0458(8) Uani 1 1 d . . . . .
C23 C 0.7035(3) 0.4689(5) 0.8806(3) 0.0563(10) Uani 1 1 d . . . . .
H23 H 0.762557 0.408504 0.850171 0.068 Uiso 1 1 calc R U . . .
C24 C 0.6950(3) 0.4625(5) 1.0004(3) 0.0642(11) Uani 1 1 d . . . . .
H24 H 0.748371 0.398931 1.049723 0.077 Uiso 1 1 calc R U . . .
C25 C 0.6077(3) 0.5502(6) 1.0460(3) 0.0639(10) Uani 1 1 d . . . . .
H25 H 0.600873 0.545024 1.126166 0.077 Uiso 1 1 calc R U . . .
C26 C 0.5299(4) 0.6462(5) 0.9726(3) 0.0654(11) Uani 1 1 d . . . . .
H26 H 0.471098 0.706545 1.003484 0.079 Uiso 1 1 calc R U . . .
C27 C 0.5395(3) 0.6525(5) 0.8531(3) 0.0582(10) Uani 1 1 d . . . . .
H27 H 0.487085 0.717615 0.804182 0.070 Uiso 1 1 calc R U . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;

loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
N1 C9 1.290(4) . ?
N1 C10 1.393(4) . ?
N2 N3 1.362(3) . ?
N2 C10 1.370(3) . ?
N2 C15 1.426(4) . ?
N3 C14 1.347(4) . ?
C1 C6 1.382(5) . ?
C1 C2 1.385(5) . ?
C1 C7 1.436(4) . ?
C2 C3 1.375(5) . ?
C2 H2 0.9300 . ?
C3 C4 1.365(6) . ?
C3 H3 0.9300 . ?
C4 C5 1.367(6) . ?
C4 H4 0.9300 . ?
C5 C6 1.392(5) . ?
C5 H5 0.9300 . ?
C6 H6 0.9300 . ?
C7 C8 1.190(4) . ?
C8 C9 1.426(4) . ?
C9 C13 1.509(5) . ?
C10 C11 1.370(4) . ?
C11 C14 1.414(4) . ?
C11 C12 1.501(4) . ?
C12 C21 1.521(5) . ?
C12 C13 1.533(5) . ?
C12 H12 0.9800 . ?
C13 H13A 0.9700 . ?
C13 H13B 0.9700 . ?
C14 C22 1.476(4) . ?
C15 C16 1.373(4) . ?
C15 C20 1.379(5) . ?
C16 C17 1.377(5) . ?
C16 H16 0.9300 . ?
C17 C18 1.380(6) . ?
C17 H17 0.9300 . ?
C18 C19 1.368(6) . ?
C18 H18 0.9300 . ?
C19 C20 1.377(5) . ?
C19 H19 0.9300 . ?
C20 H20 0.9300 . ?
C21 H21A 0.9600 . ?
C21 H21B 0.9600 . ?
C21 H21C 0.9600 . ?
C22 C23 1.377(5) . ?
C22 C27 1.383(5) . ?
C23 C24 1.386(5) . ?
C23 H23 0.9300 . ?
C24 C25 1.369(5) . ?
C24 H24 0.9300 . ?
C25 C26 1.381(6) . ?
C25 H25 0.9300 . ?
C26 C27 1.385(5) . ?
C26 H26 0.9300 . ?
C27 H27 0.9300 . ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C9 N1 C10 113.4(3) . . ?
N3 N2 C10 110.8(2) . . ?
N3 N2 C15 119.2(2) . . ?
C10 N2 C15 130.0(2) . . ?
C14 N3 N2 105.7(2) . . ?
C6 C1 C2 119.0(3) . . ?
C6 C1 C7 121.7(3) . . ?
C2 C1 C7 119.3(3) . . ?
C3 C2 C1 120.8(4) . . ?
C3 C2 H2 119.6 . . ?
C1 C2 H2 119.6 . . ?
C4 C3 C2 120.0(4) . . ?
C4 C3 H3 120.0 . . ?
C2 C3 H3 120.0 . . ?
C3 C4 C5 120.1(3) . . ?
C3 C4 H4 120.0 . . ?
C5 C4 H4 120.0 . . ?
C4 C5 C6 120.6(4) . . ?
C4 C5 H5 119.7 . . ?
C6 C5 H5 119.7 . . ?
C1 C6 C5 119.4(4) . . ?
C1 C6 H6 120.3 . . ?
C5 C6 H6 120.3 . . ?
C8 C7 C1 178.6(4) . . ?
C7 C8 C9 170.7(4) . . ?
N1 C9 C8 120.5(3) . . ?
N1 C9 C13 124.0(3) . . ?
C8 C9 C13 115.3(3) . . ?
C11 C10 N2 107.7(2) . . ?
C11 C10 N1 128.4(3) . . ?
N2 C10 N1 123.4(3) . . ?
C10 C11 C14 105.2(3) . . ?
C10 C11 C12 119.5(3) . . ?
C14 C11 C12 134.9(3) . . ?
C11 C12 C21 111.3(3) . . ?
C11 C12 C13 107.0(3) . . ?
C21 C12 C13 112.3(3) . . ?
C11 C12 H12 108.7 . . ?
C21 C12 H12 108.7 . . ?
C13 C12 H12 108.7 . . ?
C9 C13 C12 114.9(3) . . ?
C9 C13 H13A 108.6 . . ?
C12 C13 H13A 108.6 . . ?
C9 C13 H13B 108.6 . . ?
C12 C13 H13B 108.6 . . ?
H13A C13 H13B 107.5 . . ?
N3 C14 C11 110.6(2) . . ?
N3 C14 C22 119.6(2) . . ?
C11 C14 C22 129.5(3) . . ?
C16 C15 C20 120.7(3) . . ?
C16 C15 N2 120.2(3) . . ?
C20 C15 N2 119.1(3) . . ?
C15 C16 C17 119.6(4) . . ?
C15 C16 H16 120.2 . . ?
C17 C16 H16 120.2 . . ?
C16 C17 C18 120.0(4) . . ?
C16 C17 H17 120.0 . . ?
C18 C17 H17 120.0 . . ?
C19 C18 C17 119.9(4) . . ?
C19 C18 H18 120.0 . . ?
C17 C18 H18 120.0 . . ?
C18 C19 C20 120.6(4) . . ?
C18 C19 H19 119.7 . . ?
C20 C19 H19 119.7 . . ?
C19 C20 C15 119.2(4) . . ?
C19 C20 H20 120.4 . . ?
C15 C20 H20 120.4 . . ?
C12 C21 H21A 109.5 . . ?
C12 C21 H21B 109.5 . . ?
H21A C21 H21B 109.5 . . ?
C12 C21 H21C 109.5 . . ?
H21A C21 H21C 109.5 . . ?
H21B C21 H21C 109.5 . . ?
C23 C22 C27 118.3(3) . . ?
C23 C22 C14 119.5(3) . . ?
C27 C22 C14 122.1(3) . . ?
C22 C23 C24 121.3(4) . . ?
C22 C23 H23 119.3 . . ?
C24 C23 H23 119.3 . . ?
C25 C24 C23 119.8(4) . . ?
C25 C24 H24 120.1 . . ?
C23 C24 H24 120.1 . . ?
C24 C25 C26 119.8(3) . . ?
C24 C25 H25 120.1 . . ?
C26 C25 H25 120.1 . . ?
C25 C26 C27 120.0(4) . . ?
C25 C26 H26 120.0 . . ?
C27 C26 H26 120.0 . . ?
C22 C27 C26 120.7(4) . . ?
C22 C27 H27 119.6 . . ?
C26 C27 H27 119.6 . . ?

loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion_publ_flag
C10 N2 N3 C14 0.2(4) . . . . ?
C15 N2 N3 C14 -178.0(3) . . . . ?
C6 C1 C2 C3 0.3(6) . . . . ?
C7 C1 C2 C3 179.6(4) . . . . ?
C1 C2 C3 C4 -0.1(6) . . . . ?
C2 C3 C4 C5 0.4(7) . . . . ?
C3 C4 C5 C6 -0.9(7) . . . . ?
C2 C1 C6 C5 -0.7(6) . . . . ?
C7 C1 C6 C5 179.9(4) . . . . ?
C4 C5 C6 C1 1.1(7) . . . . ?
C10 N1 C9 C8 -178.7(3) . . . . ?
C10 N1 C9 C13 6.6(5) . . . . ?
N3 N2 C10 C11 0.9(4) . . . . ?
C15 N2 C10 C11 178.9(3) . . . . ?
N3 N2 C10 N1 -171.5(3) . . . . ?
C15 N2 C10 N1 6.5(6) . . . . ?
C9 N1 C10 C11 13.6(5) . . . . ?
C9 N1 C10 N2 -175.6(3) . . . . ?
N2 C10 C11 C14 -1.6(4) . . . . ?
N1 C10 C11 C14 170.3(4) . . . . ?
N2 C10 C11 C12 -175.2(3) . . . . ?
N1 C10 C11 C12 -3.3(6) . . . . ?
C10 C11 C12 C21 99.6(4) . . . . ?
C14 C11 C12 C21 -71.6(5) . . . . ?
C10 C11 C12 C13 -23.4(5) . . . . ?
C14 C11 C12 C13 165.3(4) . . . . ?
N1 C9 C13 C12 -34.7(5) . . . . ?
C8 C9 C13 C12 150.4(3) . . . . ?
C11 C12 C13 C9 39.3(4) . . . . ?
C21 C12 C13 C9 -83.1(4) . . . . ?
N2 N3 C14 C11 -1.2(4) . . . . ?
N2 N3 C14 C22 173.8(3) . . . . ?
C10 C11 C14 N3 1.8(4) . . . . ?
C12 C11 C14 N3 174.0(4) . . . . ?
C10 C11 C14 C22 -172.7(4) . . . . ?
C12 C11 C14 C22 -0.5(7) . . . . ?
N3 N2 C15 C16 -145.8(3) . . . . ?
C10 N2 C15 C16 36.4(5) . . . . ?
N3 N2 C15 C20 32.3(4) . . . . ?
C10 N2 C15 C20 -145.6(4) . . . . ?
C20 C15 C16 C17 0.8(6) . . . . ?
N2 C15 C16 C17 178.8(3) . . . . ?
C15 C16 C17 C18 -1.0(6) . . . . ?
C16 C17 C18 C19 0.6(7) . . . . ?
C17 C18 C19 C20 0.0(7) . . . . ?
C18 C19 C20 C15 -0.2(6) . . . . ?
C16 C15 C20 C19 -0.1(5) . . . . ?
N2 C15 C20 C19 -178.2(3) . . . . ?
N3 C14 C22 C23 -30.4(5) . . . . ?
C11 C14 C22 C23 143.6(4) . . . . ?
N3 C14 C22 C27 152.8(3) . . . . ?
C11 C14 C22 C27 -33.2(6) . . . . ?
C27 C22 C23 C24 0.3(5) . . . . ?
C14 C22 C23 C24 -176.6(3) . . . . ?
C22 C23 C24 C25 0.5(6) . . . . ?
C23 C24 C25 C26 -1.0(6) . . . . ?
C24 C25 C26 C27 0.6(6) . . . . ?
C23 C22 C27 C26 -0.7(6) . . . . ?
C14 C22 C27 C26 176.2(3) . . . . ?
C25 C26 C27 C22 0.2(6) . . . . ?

_refine_diff_density_max         0.114
_refine_diff_density_min         -0.171
_refine_diff_density_rms         0.033



