# Supplementary Information (SI) for Chemical Science.
# 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_SEA2_PbI4
_database_code_depnum_ccdc_archive 'CCDC 2348172'
loop_
_audit_author_name
_audit_author_address
'Wenxuan Li'
;Sun Yat sen University
China
;
_audit_update_record             
;
2024-04-14 deposited with the CCDC.	2026-03-09 downloaded from the CCDC.
;
_audit_creation_date             2024-04-14
_audit_creation_method           
;
Olex2 1.5
(compiled 2024.02.16 svn.r378c4104 for OlexSys, GUI svn.r6928)
;
_shelx_SHELXL_version_number     2014/7
_chemical_name_common            ?
_chemical_name_systematic        SEA2_PbI4
_chemical_formula_moiety         'I4 Pb, 2(C2 H8 N Se)'
_chemical_formula_sum            'C4 H16 I4 N2 Pb Se2'
_chemical_formula_weight         964.90
_chemical_melting_point          ?
_chemical_oxdiff_formula         CHNSePbI
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'
I I -0.4742 1.8119 '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'
Pb Pb -3.3944 10.1111 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Se Se -0.0929 2.2259 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_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.
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_H-M_alt        'P 1 21/c 1'
_space_group_name_Hall           '-P 2ybc'
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                   12.2377(6)
_cell_length_b                   8.7867(4)
_cell_length_c                   8.6139(4)
_cell_angle_alpha                90
_cell_angle_beta                 98.546(4)
_cell_angle_gamma                90
_cell_volume                     915.96(8)
_cell_formula_units_Z            2
_cell_measurement_reflns_used    5371
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      30.4100
_cell_measurement_theta_min      3.3060
_shelx_estimated_absorpt_T_max   ?
_shelx_estimated_absorpt_T_min   ?
_exptl_absorpt_coefficient_mu    19.899
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.31169
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
;
CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            orange
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    3.499
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             832
_exptl_crystal_size_max          ?
_exptl_crystal_size_mid          ?
_exptl_crystal_size_min          ?
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0279
_diffrn_reflns_av_unetI/netI     0.0312
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.792
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            7342
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.792
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.813
_diffrn_reflns_theta_min         2.865
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100.00(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.792
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω    -26.00  61.00   0.50    0.30    --   -7.90  57.00 -95.00  174
  2  ω     -8.00  17.00   0.50    0.30    --   -7.90 -99.00 -30.00   50
  3  ω    -14.00  20.00   0.50    0.30    --   -7.90 -99.00   0.00   68
  4  ω    -81.00 -14.00   0.50    0.30    --   -7.90 -57.00 122.00  134
  5  ω    -17.00  27.00   0.50    0.30    --   -7.90 -99.00 150.00   88
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, DW system, HyPix'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0209512000
_diffrn_orient_matrix_UB_12      0.0537123000
_diffrn_orient_matrix_UB_13      -0.0495032000
_diffrn_orient_matrix_UB_21      -0.0543246000
_diffrn_orient_matrix_UB_22      0.0133538000
_diffrn_orient_matrix_UB_23      -0.0392805000
_diffrn_orient_matrix_UB_31      -0.0068626000
_diffrn_orient_matrix_UB_32      0.0587830000
_diffrn_orient_matrix_UB_33      0.0541627000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Mo) X-ray Source'
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                2019
_reflns_number_total             2276
_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.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2014/7 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/4 (Sheldrick, 2014)'
_refine_diff_density_max         1.017
_refine_diff_density_min         -0.815
_refine_diff_density_rms         0.199
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.075
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     66
_refine_ls_number_reflns         2276
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0266
_refine_ls_R_factor_gt           0.0209
_refine_ls_restrained_S_all      1.075
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.0131P)²+1.4770P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0425
_refine_ls_wR_factor_ref         0.0441
_refine_special_details          ?
_olex2_refinement_description    
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups
 At 1.5 times of:
  All N(H,H,H) groups
2.a Secondary CH2 refined with riding coordinates:
 C006(H00D,H00E), C007(H00F,H00G)
2.b Idealised Me refined as rotating group:
 N005(H00A,H00B,H00C)
;
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   ?
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
Pb01 Pb 0.5000 0.0000 0.5000 0.01189(6) Uani 1 2 d S . P . .
I002 I 0.44877(3) 0.30172(3) 0.68517(3) 0.01585(8) Uani 1 1 d . . . . .
I003 I 0.75374(3) 0.08939(3) 0.53036(3) 0.01797(8) Uani 1 1 d . . . . .
Se04 Se 0.98520(4) 0.78178(6) 0.61651(6) 0.02308(12) Uani 1 1 d . . . . .
N005 N 0.7177(4) 0.4760(4) 0.6141(5) 0.0230(9) Uani 1 1 d . . . . .
H00A H 0.7046 0.3845 0.5652 0.035 Uiso 1 1 calc R U . . .
H00B H 0.6612 0.5409 0.5805 0.035 Uiso 1 1 calc R U . . .
H00C H 0.7229 0.4630 0.7197 0.035 Uiso 1 1 calc R U . . .
C006 C 0.8243(4) 0.5413(5) 0.5756(5) 0.0190(10) Uani 1 1 d . . . . .
H00D H 0.8164 0.5664 0.4625 0.023 Uiso 1 1 calc R U . . .
H00E H 0.8844 0.4655 0.5992 0.023 Uiso 1 1 calc R U . . .
C007 C 0.8527(4) 0.6837(5) 0.6726(6) 0.0205(10) Uani 1 1 d . . . . .
H00F H 0.8653 0.6567 0.7855 0.025 Uiso 1 1 calc R U . . .
H00G H 0.7898 0.7557 0.6548 0.025 Uiso 1 1 calc R U . . .
H04 H 1.056(5) 0.688(6) 0.689(7) 0.041(17) Uiso 1 1 d . . . . .

loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_23
_atom_site_aniso_U_13
_atom_site_aniso_U_12
Pb01 0.01184(14) 0.01249(11) 0.01148(11) 0.00009(7) 0.00227(9) -0.00083(8)
I002 0.01868(18) 0.01607(14) 0.01287(14) -0.00482(10) 0.00261(12) -0.00028(11)
I003 0.01246(17) 0.01776(15) 0.02367(16) -0.00238(10) 0.00265(12) -0.00240(11)
Se04 0.0170(3) 0.0312(3) 0.0207(2) 0.00099(18) 0.0016(2) -0.0048(2)
N005 0.025(3) 0.020(2) 0.025(2) 0.0026(15) 0.0055(19) -0.0033(17)
C006 0.018(3) 0.020(2) 0.018(2) 0.0036(17) 0.002(2) 0.0014(18)
C007 0.018(3) 0.021(2) 0.023(2) 0.0009(18) 0.008(2) -0.0040(18)

_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
Pb01 I002 3.2036(3) 3_656 ?
Pb01 I002 3.2058(3) 4_565 ?
Pb01 I002 3.2058(3) 2_646 ?
Pb01 I002 3.2036(3) . ?
Pb01 I003 3.1758(3) . ?
Pb01 I003 3.1758(3) 3_656 ?
I002 Pb01 3.2058(3) 2_656 ?
Se04 C007 1.959(5) . ?
Se04 H04 1.29(6) . ?
N005 H00A 0.9100 . ?
N005 H00B 0.9100 . ?
N005 H00C 0.9100 . ?
N005 C006 1.507(7) . ?
C006 H00D 0.9900 . ?
C006 H00E 0.9900 . ?
C006 C007 1.516(6) . ?
C007 H00F 0.9900 . ?
C007 H00G 0.9900 . ?

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
I002 Pb01 I002 180.0 3_656 . ?
I002 Pb01 I002 180.0 2_646 4_565 ?
I002 Pb01 I002 86.750(4) . 4_565 ?
I002 Pb01 I002 86.750(4) 3_656 2_646 ?
I002 Pb01 I002 93.250(4) 3_656 4_565 ?
I002 Pb01 I002 93.250(5) . 2_646 ?
I003 Pb01 I002 90.067(8) 3_656 2_646 ?
I003 Pb01 I002 90.067(8) . 4_565 ?
I003 Pb01 I002 90.895(8) . . ?
I003 Pb01 I002 89.933(8) . 2_646 ?
I003 Pb01 I002 89.105(8) 3_656 . ?
I003 Pb01 I002 90.896(8) 3_656 3_656 ?
I003 Pb01 I002 89.933(8) 3_656 4_565 ?
I003 Pb01 I002 89.105(8) . 3_656 ?
I003 Pb01 I003 180.0 3_656 . ?
Pb01 I002 Pb01 147.434(10) . 2_656 ?
C007 Se04 H04 97(3) . . ?
H00A N005 H00B 109.5 . . ?
H00A N005 H00C 109.5 . . ?
H00B N005 H00C 109.5 . . ?
C006 N005 H00A 109.5 . . ?
C006 N005 H00B 109.5 . . ?
C006 N005 H00C 109.5 . . ?
N005 C006 H00D 109.9 . . ?
N005 C006 H00E 109.9 . . ?
N005 C006 C007 109.1(4) . . ?
H00D C006 H00E 108.3 . . ?
C007 C006 H00D 109.9 . . ?
C007 C006 H00E 109.9 . . ?
Se04 C007 H00F 109.5 . . ?
Se04 C007 H00G 109.5 . . ?
C006 C007 Se04 110.9(3) . . ?
C006 C007 H00F 109.5 . . ?
C006 C007 H00G 109.5 . . ?
H00F C007 H00G 108.0 . . ?

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
N005 C006 C007 Se04 -175.9(3) . . . . ?

_shelx_res_file                  
;
    dsea-0.6_auto.res created by SHELXL-2014/7

TITL dsea-0.6_auto_a.res in P2(1)/c
REM Old TITL DSEA-0 in P2(1)/c
REM SHELXT solution in P2(1)/c
REM R1 0.053, Rweak 0.003, Alpha 0.010, Orientation as input
REM Formula found by SHELXT: N6 Se2 I4 Pb
CELL 0.71073 12.2377 8.7867 8.6139 90 98.546 90
ZERR 2 0.0006 0.0004 0.0004 0 0.004 0
LATT 1
SYMM -X,0.5+Y,0.5-Z
SFAC C H I N Pb Se
UNIT 8 32 8 4 2 4

L.S. 4
PLAN  8
TEMP -173
CONF
list 4
MORE -1
BOND $H
fmap 2
acta
REM <olex2.extras>
REM <HklSrc "%.\\DSEA-0.6_auto.hkl">
REM </olex2.extras>

WGHT    0.013100    1.477000
FVAR       0.22483
PB01  5    0.500000    0.000000    0.500000    10.50000    0.01184    0.01249 =
         0.01148    0.00009    0.00227   -0.00083
I002  3    0.448768    0.301725    0.685174    11.00000    0.01868    0.01607 =
         0.01287   -0.00482    0.00261   -0.00028
I003  3    0.753736    0.089394    0.530362    11.00000    0.01246    0.01776 =
         0.02367   -0.00238    0.00265   -0.00240
SE04  6    0.985196    0.781785    0.616512    11.00000    0.01700    0.03119 =
         0.02070    0.00099    0.00164   -0.00482
N005  4    0.717666    0.475964    0.614060    11.00000    0.02451    0.02041 =
         0.02476    0.00262    0.00546   -0.00325
AFIX 137
H00A  2    0.704580    0.384525    0.565225    11.00000   -1.50000
H00B  2    0.661159    0.540902    0.580451    11.00000   -1.50000
H00C  2    0.722857    0.463022    0.719717    11.00000   -1.50000
AFIX   0
C006  1    0.824334    0.541288    0.575613    11.00000    0.01820    0.02045 =
         0.01819    0.00363    0.00185    0.00141
AFIX  23
H00D  2    0.816379    0.566414    0.462456    11.00000   -1.20000
H00E  2    0.884394    0.465545    0.599235    11.00000   -1.20000
AFIX   0
C007  1    0.852668    0.683713    0.672631    11.00000    0.01806    0.02149 =
         0.02339    0.00089    0.00768   -0.00399
AFIX  23
H00F  2    0.865315    0.656738    0.785465    11.00000   -1.20000
H00G  2    0.789823    0.755704    0.654799    11.00000   -1.20000
AFIX   0
H04   2    1.056131    0.687882    0.688950    11.00000    0.04054
HKLF 4

REM  dsea-0.6_auto_a.res in P2(1)/c
REM R1 =  0.0209 for    2019 Fo > 4sig(Fo)  and  0.0266 for all    2276 data
REM     66 parameters refined using      0 restraints

END

WGHT      0.0131      1.4769

REM Highest difference peak  1.017,  deepest hole -0.815,  1-sigma level  0.199
Q1    1   0.4221 -0.0168  0.4263  11.00000  0.05    1.02
Q2    1   0.4920  0.1953  0.5041  11.00000  0.05    0.83
Q3    1   0.6667  0.0849  0.4614  11.00000  0.05    0.72
Q4    1   0.5542  0.1998  0.8315  11.00000  0.05    0.71
Q5    1   0.9773  0.4607  0.5118  11.00000  0.05    0.70
Q6    1   0.5235  0.1044  0.4266  11.00000  0.05    0.69
Q7    1   0.3583  0.4207  0.8402  11.00000  0.05    0.68
Q8    1   1.0173  0.6961  0.6427  11.00000  0.05    0.67
;
_shelx_res_checksum              98914
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details 
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 2.274
_oxdiff_exptl_absorpt_empirical_full_min 0.560
