# Supplementary Information (SI) for Organic & Biomolecular Chemistry.
# This journal is © The Royal Society of Chemistry 2025

####################################################################### 
# 
# 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_f
_database_code_depnum_ccdc_archive 'CCDC 2484494'
loop_
_audit_author_name
_audit_author_address
'Farukh Ahmad'
;IIT Roorkee
India
;
_audit_update_record             
;
2025-09-02 deposited with the CCDC.	2025-11-26 downloaded from the CCDC.
;

_audit_creation_method           SHELXL-2019/1
_shelx_SHELXL_version_number     2019/1
_chemical_name_systematic        ?
_chemical_name_common            ?
_chemical_melting_point          ?
_chemical_formula_moiety         'C24 H17 N O4'
_chemical_formula_sum            'C24 H17 N O4'
_chemical_formula_weight         383.38

loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 '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 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_H-M_alt        'P 21/c'
_space_group_name_Hall           '-P 2ybc'

_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+1/2'
'-x, -y, -z'
'x, -y-1/2, z-1/2'

_cell_length_a                   20.836(4)
_cell_length_b                   7.1335(13)
_cell_length_c                   21.837(5)
_cell_angle_alpha                90
_cell_angle_beta                 146.592(5)
_cell_angle_gamma                90
_cell_volume                     1787.1(6)
_cell_formula_units_Z            4
_cell_measurement_temperature    300(2)
_cell_measurement_reflns_used    6533
_cell_measurement_theta_min      3.0257
_cell_measurement_theta_max      19.6732

_exptl_crystal_description       block
_exptl_crystal_colour            'lusterous light yellow'
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_density_diffrn    1.425
_exptl_crystal_F_000             800
_exptl_transmission_factor_min   ?
_exptl_transmission_factor_max   ?
_exptl_crystal_size_max          0.219
_exptl_crystal_size_mid          0.206
_exptl_crystal_size_min          0.089
_exptl_absorpt_coefficient_mu    0.098
_shelx_estimated_absorpt_T_min   0.979
_shelx_estimated_absorpt_T_max   0.991
_exptl_absorpt_correction_type   Multi-Scan
_exptl_absorpt_correction_T_min  0.91
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_process_details   
;
Krause, L., Herbst-Irmer, R., Sheldrick, G. M., Stalke, D. (2015).
"Comparison of silver and molybdenum microfocus X-ray sources for
single-crystal structure determination"
J. Appl. Cryst. 48, 3-10.
doi:10.1107/S1600576714022985
;

_exptl_absorpt_special_details   ?
_diffrn_ambient_temperature      300(2)
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_type           MoK\a
_diffrn_source                   'micro-focus sealed tube'
_diffrn_measurement_device_type  'Bruker D8 QUEST photon III C7'
_diffrn_measurement_method       '\ f and \ w scans'
_diffrn_detector_area_resol_mean 7.3910
_diffrn_reflns_number            3218
_diffrn_reflns_av_unetI/netI     0.0347
_diffrn_reflns_av_R_equivalents  ?
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_theta_min         2.000
_diffrn_reflns_theta_max         25.209
_diffrn_reflns_theta_full        25.209
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measured_fraction_theta_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_point_group_measured_fraction_full 0.997
_reflns_number_total             3218
_reflns_number_gt                2384
_reflns_threshold_expression     'I > 2σ(I)'
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_max     .
_reflns_Friedel_fraction_full    .

_reflns_special_details          
;
 _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. Completness statistics refer to single and
 composite reflections containing twin component 1 only.
;

_computing_data_collection       
"Bruker APEX4 v2022.1-0'(Bruker AXS Inc., 2022)"
_computing_cell_refinement       'SAINT V8.40B (Bruker AXS LLC, 2019)'
_computing_data_reduction        'SAINT V8.40B (Bruker AXS LLC, 2019)'
_computing_structure_solution    'XT, VERSION 2018/2'
_computing_structure_refinement  'SHELXL-2019/1 (Sheldrick, 2019)'
_computing_molecular_graphics    'shelXle (C.B. Huebschle, rev 1380)'
_computing_publication_material  "APEX4 v2022.1-0'(Bruker AXS Inc., 2022)"
_refine_special_details          
;
 Refined as a 2-component twin.
;
_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.0822P)²+1.0200P] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
_atom_sites_solution_hydrogens   mixed
_refine_ls_hydrogen_treatment    mixed
_refine_ls_extinction_method     none
_refine_ls_extinction_coef       .
_refine_ls_number_reflns         3218
_refine_ls_number_parameters     307
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0824
_refine_ls_R_factor_gt           0.0618
_refine_ls_wR_factor_ref         0.1864
_refine_ls_wR_factor_gt          0.1685
_refine_ls_goodness_of_fit_ref   1.095
_refine_ls_restrained_S_all      1.095
_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
O1 O 0.06512(18) 0.3631(3) -0.40217(17) 0.0583(6) Uani 1 1 d . . . . .
O2 O 0.10882(18) 0.2671(3) -0.18514(17) 0.0549(6) Uani 1 1 d . . . . .
O3 O -0.20669(17) 0.0741(3) -0.49682(16) 0.0506(5) Uani 1 1 d . . . . .
O4 O -0.3448(2) 0.1869(4) -0.5130(2) 0.0778(8) Uani 1 1 d . . . . .
N1 N -0.2187(2) 0.4663(4) -0.5135(2) 0.0511(7) Uani 1 1 d . . . . .
C1 C 0.1930(3) 0.2899(4) -0.2165(2) 0.0458(7) Uani 1 1 d . . . . .
C3 C 0.1743(3) 0.3252(4) -0.2927(3) 0.0500(8) Uani 1 1 d . . . . .
C4 C 0.2640(3) 0.3244(5) -0.2634(3) 0.0624(9) Uani 1 1 d . . . . .
C5 C 0.3962(3) 0.2535(7) -0.0761(4) 0.0776(12) Uani 1 1 d . . . . .
C6 C 0.3057(3) 0.2532(5) -0.1075(3) 0.0619(9) Uani 1 1 d . . . . .
H6 H 0.319959 0.228008 -0.055048 0.074 Uiso 1 1 calc R U . . .
C7 C 0.0957(3) 0.2973(4) -0.2508(2) 0.0447(7) Uani 1 1 d . . . . .
C8 C -0.0159(3) 0.3482(4) -0.3661(2) 0.0461(7) Uani 1 1 d . . . . .
C9 C -0.0244(3) 0.3783(5) -0.4331(3) 0.0552(8) Uani 1 1 d . . . . .
C10 C -0.1194(2) 0.3764(4) -0.4058(2) 0.0483(7) Uani 1 1 d . . . . .
H10 H -0.093897 0.455336 -0.351248 0.058 Uiso 1 1 calc R U . . .
C11 C -0.1566(3) 0.1857(4) -0.4093(3) 0.0473(7) Uani 1 1 d . . . . .
C12 C -0.2920(2) 0.1613(4) -0.5991(2) 0.0458(7) Uani 1 1 d . . . . .
C13 C -0.3012(2) 0.3558(4) -0.6083(2) 0.0456(7) Uani 1 1 d . . . . .
C14 C -0.2414(3) 0.2108(5) -0.4231(3) 0.0533(8) Uani 1 1 d . . . . .
C15 C -0.1944(3) 0.2655(4) -0.3242(3) 0.0506(8) Uani 1 1 d . . . . .
C16 C -0.2337(4) 0.3195(6) -0.2491(4) 0.0693(10) Uani 1 1 d . . . . .
C17 C -0.2715(3) 0.2738(5) -0.3371(3) 0.0646(9) Uani 1 1 d . . . . .
H17 H -0.350035 0.248169 -0.406118 0.078 Uiso 1 1 calc R U . . .
C18 C -0.1191(4) 0.3583(5) -0.1476(3) 0.0660(10) Uani 1 1 d . . . . .
H18 H -0.093982 0.389635 -0.088446 0.079 Uiso 1 1 calc R U . . .
C19 C -0.0397(3) 0.3511(5) -0.1322(3) 0.0598(9) Uani 1 1 d . . . . .
C20 C -0.0780(3) 0.3038(5) -0.2205(3) 0.0531(8) Uani 1 1 d . . . . .
H20 H -0.024881 0.297539 -0.210300 0.064 Uiso 1 1 calc R U . . .
C21 C -0.3688(3) 0.0508(5) -0.6925(3) 0.0571(8) Uani 1 1 d . . . . .
C22 C -0.4586(3) 0.1308(6) -0.7966(3) 0.0657(10) Uani 1 1 d . . . . .
C23 C -0.4718(3) 0.3207(6) -0.8070(3) 0.0628(9) Uani 1 1 d . . . . .
C24 C -0.3934(3) 0.4324(5) -0.7136(3) 0.0565(8) Uani 1 1 d . . . . .
H24 H -0.402804 0.561869 -0.721810 0.068 Uiso 1 1 calc R U . . .
C2 C 0.3750(3) 0.2908(6) -0.1544(3) 0.0743(11) Uani 1 1 d . . . . .
H11 H -0.086(2) 0.113(4) -0.340(2) 0.038(7) Uiso 1 1 d . . . . .
H22 H -0.517(3) 0.046(5) -0.861(3) 0.074(11) Uiso 1 1 d . . . . .
H23 H -0.539(3) 0.385(5) -0.880(3) 0.086(12) Uiso 1 1 d . . . . .
H9 H -0.101(3) 0.418(5) -0.519(3) 0.087(12) Uiso 1 1 d . . . . .
H21 H -0.354(3) -0.067(5) -0.675(3) 0.072(12) Uiso 1 1 d . . . . .
H4 H 0.242(3) 0.349(5) -0.320(3) 0.070(11) Uiso 1 1 d . . . . .
H19 H 0.047(3) 0.391(6) -0.054(3) 0.086(12) Uiso 1 1 d . . . . .
H1 H -0.239(3) 0.557(6) -0.514(3) 0.075(13) Uiso 1 1 d . . . . .
H2 H 0.443(4) 0.291(6) -0.132(4) 0.100(14) Uiso 1 1 d . . . . .
H5 H 0.475(5) 0.229(7) 0.003(4) 0.119(17) Uiso 1 1 d . . . . .
H16 H -0.291(3) 0.325(5) -0.263(3) 0.076(11) Uiso 1 1 d . . . . .


_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
O1 C9 1.357(4) . ?
O1 C3 1.372(4) . ?
O2 C7 1.233(3) . ?
O3 C12 1.381(3) . ?
O3 C11 1.431(4) . ?
O4 C14 1.210(4) . ?
N1 C13 1.386(4) . ?
N1 C10 1.450(4) . ?
N1 H1 0.77(4) . ?
C1 C3 1.380(4) . ?
C1 C6 1.385(4) . ?
C1 C7 1.463(4) . ?
C3 C4 1.379(4) . ?
C4 C2 1.372(5) . ?
C4 H4 0.90(4) . ?
C5 C6 1.365(5) . ?
C5 C2 1.391(6) . ?
C5 H5 0.98(5) . ?
C6 H6 0.9300 . ?
C7 C8 1.450(4) . ?
C8 C9 1.338(4) . ?
C8 C10 1.525(4) . ?
C9 H9 1.07(4) . ?
C10 C11 1.535(4) . ?
C10 H10 0.9800 . ?
C11 C14 1.536(4) . ?
C11 H11 1.00(3) . ?
C12 C21 1.376(4) . ?
C12 C13 1.392(4) . ?
C13 C24 1.379(4) . ?
C14 C15 1.497(5) . ?
C15 C17 1.383(5) . ?
C15 C20 1.384(4) . ?
C16 C18 1.362(5) . ?
C16 C17 1.374(5) . ?
C16 H16 0.96(4) . ?
C17 H17 0.9300 . ?
C18 C19 1.387(5) . ?
C18 H18 0.9300 . ?
C19 C20 1.378(5) . ?
C19 H19 1.06(4) . ?
C20 H20 0.9300 . ?
C21 C22 1.376(5) . ?
C21 H21 0.87(4) . ?
C22 C23 1.363(6) . ?
C22 H22 0.98(4) . ?
C23 C24 1.378(5) . ?
C23 H23 0.99(4) . ?
C24 H24 0.9300 . ?
C2 H2 1.05(5) . ?

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 O1 C3 118.3(2) . . ?
C12 O3 C11 115.4(2) . . ?
C13 N1 C10 118.9(3) . . ?
C13 N1 H1 118(3) . . ?
C10 N1 H1 115(3) . . ?
C3 C1 C6 118.3(3) . . ?
C3 C1 C7 120.1(3) . . ?
C6 C1 C7 121.6(3) . . ?
O1 C3 C4 116.3(3) . . ?
O1 C3 C1 121.6(3) . . ?
C4 C3 C1 122.0(3) . . ?
C2 C4 C3 118.4(3) . . ?
C2 C4 H4 127(2) . . ?
C3 C4 H4 115(2) . . ?
C6 C5 C2 119.7(4) . . ?
C6 C5 H5 118(3) . . ?
C2 C5 H5 123(3) . . ?
C5 C6 C1 120.9(3) . . ?
C5 C6 H6 119.6 . . ?
C1 C6 H6 119.6 . . ?
O2 C7 C8 122.7(3) . . ?
O2 C7 C1 122.1(3) . . ?
C8 C7 C1 115.2(3) . . ?
C9 C8 C7 119.8(3) . . ?
C9 C8 C10 121.7(3) . . ?
C7 C8 C10 118.5(3) . . ?
C8 C9 O1 124.8(3) . . ?
C8 C9 H9 127(2) . . ?
O1 C9 H9 109(2) . . ?
N1 C10 C8 113.9(3) . . ?
N1 C10 C11 109.6(2) . . ?
C8 C10 C11 109.1(2) . . ?
N1 C10 H10 108.0 . . ?
C8 C10 H10 108.0 . . ?
C11 C10 H10 108.0 . . ?
O3 C11 C10 109.5(2) . . ?
O3 C11 C14 111.5(2) . . ?
C10 C11 C14 110.9(3) . . ?
O3 C11 H11 104.3(15) . . ?
C10 C11 H11 109.9(15) . . ?
C14 C11 H11 110.5(15) . . ?
C21 C12 O3 118.3(3) . . ?
C21 C12 C13 120.5(3) . . ?
O3 C12 C13 121.3(3) . . ?
C24 C13 N1 122.0(3) . . ?
C24 C13 C12 117.9(3) . . ?
N1 C13 C12 120.1(3) . . ?
O4 C14 C15 120.9(3) . . ?
O4 C14 C11 120.0(3) . . ?
C15 C14 C11 119.1(3) . . ?
C17 C15 C20 118.5(3) . . ?
C17 C15 C14 117.9(3) . . ?
C20 C15 C14 123.6(3) . . ?
C18 C16 C17 120.2(4) . . ?
C18 C16 H16 123(2) . . ?
C17 C16 H16 117(2) . . ?
C16 C17 C15 120.9(4) . . ?
C16 C17 H17 119.6 . . ?
C15 C17 H17 119.6 . . ?
C16 C18 C19 120.2(3) . . ?
C16 C18 H18 119.9 . . ?
C19 C18 H18 119.9 . . ?
C20 C19 C18 119.3(3) . . ?
C20 C19 H19 122(2) . . ?
C18 C19 H19 118(2) . . ?
C19 C20 C15 121.0(3) . . ?
C19 C20 H20 119.5 . . ?
C15 C20 H20 119.5 . . ?
C22 C21 C12 120.4(4) . . ?
C22 C21 H21 128(3) . . ?
C12 C21 H21 111(3) . . ?
C23 C22 C21 119.6(4) . . ?
C23 C22 H22 122(2) . . ?
C21 C22 H22 118(2) . . ?
C22 C23 C24 120.2(3) . . ?
C22 C23 H23 123(2) . . ?
C24 C23 H23 117(2) . . ?
C23 C24 C13 121.2(3) . . ?
C23 C24 H24 119.4 . . ?
C13 C24 H24 119.4 . . ?
C4 C2 C5 120.8(3) . . ?
C4 C2 H2 118(2) . . ?
C5 C2 H2 121(2) . . ?

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
C9 O1 C3 C4 -175.5(3) . . . . ?
C9 O1 C3 C1 4.5(5) . . . . ?
C6 C1 C3 O1 -179.9(3) . . . . ?
C7 C1 C3 O1 -1.7(5) . . . . ?
C6 C1 C3 C4 0.2(5) . . . . ?
C7 C1 C3 C4 178.3(3) . . . . ?
O1 C3 C4 C2 178.8(3) . . . . ?
C1 C3 C4 C2 -1.3(6) . . . . ?
C2 C5 C6 C1 -0.1(6) . . . . ?
C3 C1 C6 C5 0.5(5) . . . . ?
C7 C1 C6 C5 -177.6(3) . . . . ?
C3 C1 C7 O2 -179.8(3) . . . . ?
C6 C1 C7 O2 -1.7(5) . . . . ?
C3 C1 C7 C8 -1.6(4) . . . . ?
C6 C1 C7 C8 176.5(3) . . . . ?
O2 C7 C8 C9 -179.7(3) . . . . ?
C1 C7 C8 C9 2.1(4) . . . . ?
O2 C7 C8 C10 3.6(4) . . . . ?
C1 C7 C8 C10 -174.6(3) . . . . ?
C7 C8 C9 O1 0.7(5) . . . . ?
C10 C8 C9 O1 177.3(3) . . . . ?
C3 O1 C9 C8 -4.1(5) . . . . ?
C13 N1 C10 C8 88.7(3) . . . . ?
C13 N1 C10 C11 -33.8(4) . . . . ?
C9 C8 C10 N1 -9.6(4) . . . . ?
C7 C8 C10 N1 167.0(3) . . . . ?
C9 C8 C10 C11 113.1(3) . . . . ?
C7 C8 C10 C11 -70.3(3) . . . . ?
C12 O3 C11 C10 -50.0(3) . . . . ?
C12 O3 C11 C14 73.1(3) . . . . ?
N1 C10 C11 O3 56.1(3) . . . . ?
C8 C10 C11 O3 -69.3(3) . . . . ?
N1 C10 C11 C14 -67.4(3) . . . . ?
C8 C10 C11 C14 167.3(3) . . . . ?
C11 O3 C12 C21 -159.5(3) . . . . ?
C11 O3 C12 C13 20.1(4) . . . . ?
C10 N1 C13 C24 -175.4(3) . . . . ?
C10 N1 C13 C12 3.9(4) . . . . ?
C21 C12 C13 C24 3.9(4) . . . . ?
O3 C12 C13 C24 -175.7(3) . . . . ?
C21 C12 C13 N1 -175.4(3) . . . . ?
O3 C12 C13 N1 5.0(4) . . . . ?
O3 C11 C14 O4 -20.4(4) . . . . ?
C10 C11 C14 O4 102.0(4) . . . . ?
O3 C11 C14 C15 159.8(3) . . . . ?
C10 C11 C14 C15 -77.8(4) . . . . ?
O4 C14 C15 C17 4.8(5) . . . . ?
C11 C14 C15 C17 -175.4(3) . . . . ?
O4 C14 C15 C20 -176.7(3) . . . . ?
C11 C14 C15 C20 3.1(5) . . . . ?
C18 C16 C17 C15 0.3(6) . . . . ?
C20 C15 C17 C16 0.2(5) . . . . ?
C14 C15 C17 C16 178.7(3) . . . . ?
C17 C16 C18 C19 -0.3(6) . . . . ?
C16 C18 C19 C20 -0.2(5) . . . . ?
C18 C19 C20 C15 0.7(5) . . . . ?
C17 C15 C20 C19 -0.7(5) . . . . ?
C14 C15 C20 C19 -179.1(3) . . . . ?
O3 C12 C21 C22 177.0(3) . . . . ?
C13 C12 C21 C22 -2.6(5) . . . . ?
C12 C21 C22 C23 -0.5(5) . . . . ?
C21 C22 C23 C24 2.2(5) . . . . ?
C22 C23 C24 C13 -0.8(5) . . . . ?
N1 C13 C24 C23 177.1(3) . . . . ?
C12 C13 C24 C23 -2.2(4) . . . . ?
C3 C4 C2 C5 1.7(6) . . . . ?
C6 C5 C2 C4 -1.0(7) . . . . ?

_refine_diff_density_max         0.219
_refine_diff_density_min         -0.190
_refine_diff_density_rms         0.043

