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Structure info
Layer group p-6m2
Layer group number 78
Structure origin original03-18
Stability
Energy above convex hull [eV/atom] 0.078
Heat of formation [eV/atom] -0.614
Dynamically stable Yes
Basic properties
Magnetic No
Band gap (PBE) [eV] 1.577
Band gap (HSE06) [eV] 2.404
Band gap (G₀W₀) [eV] 3.338
  XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 4.502 0.000 0.000 Yes
2 -2.251 3.899 0.000 Yes
3 0.000 0.000 19.062 No
Lengths [Å] 4.502 4.502 19.062
Angles [°] 90.000 90.000 120.000

Symmetries
2D Bravais type Hexagonal (hp)
Layer group number 78
Layer group p-6m2
Space group number (bulk in AA-stacking) 187
Space group (bulk in AA-stacking) P-6m2
Point group -6m2
Inversion symmetry No
Structure data
Formula PbI2
Stoichiometry AB2
Number of atoms 3
Unit cell area [Å2] 17.556
Thickness [Å] 4.062

PbI2 (1PbI2-2)
Heat of formation [eV/atom] -0.61
Energy above convex hull [eV/atom] 0.08
Monolayers from C2DB
PbI2 (1PbI2-1) -0.69 eV/atom
Pb6I12 (6PbI2-1) -0.66 eV/atom
Pb2I4 (2PbI2-1) -0.64 eV/atom
Pb2I4 (2PbI2-2) -0.62 eV/atom
PbI2, (1PbI2-2) -0.61 eV/atom
Pb2I4 (2PbI2-3) -0.60 eV/atom
PbI2 (1PbI2-3) -0.55 eV/atom
I2Pb2 (2IPb-1) -0.20 eV/atom
I2Pb2 (2IPb-2) -0.19 eV/atom
Bulk crystals from OQMD123
I8Pb4 -0.69 eV/atom
I4 0.00 eV/atom
Pb 0.00 eV/atom

AB2/1PbI2/2/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

DVB [eV] xx yy xy
Γ -2.58 -2.60 0.00
M 1.01 1.02 0.00
K 0.32 0.35 0.01
kVBM -3.36 -2.41 -0.80
xx yy xy
Band gap [eV] -0.78 -1.72 0.80
DCB [eV] xx yy xy
Γ -4.14 -4.13 0.00
M 0.02 -1.36 1.12
K 1.48 1.56 0.02
kCBM -4.14 -4.13 0.00

Cij (N/m) xx yy xy
xx 16.36 9.27 -0.07
yy 9.48 16.12 -0.07
xy 0.00 0.00 7.04
Stiffness tensor eigenvalues
Eigenvalue 0 6.87 N/m
Eigenvalue 1 7.04 N/m
Eigenvalue 2 25.61 N/m

cij [e/Å] xx yy xy
x 0.00 0.00 -0.23
y -0.20 0.20 -0.00
z 0.00 -0.00 0.00
cijclamped [e/Å] xx yy xy
x 0.00 0.00 -0.23
y -0.23 0.23 -0.00
z -0.00 0.00 0.00

Key values [eV]
Band gap (PBE) 1.577
Direct band gap (PBE) 1.628
Valence band maximum wrt. vacuum (PBE) -6.240
Conduction band minimum wrt. vacuum (PBE) -4.663
DOS BZ

Key values [eV]
Band gap (HSE06) 2.404
Direct band gap (HSE06) 2.543
Valence band maximum wrt. vacuum (HSE06) -6.737
Conduction band minimum wrt. vacuum (HSE06) -4.333

Key values [eV]
Band gap (G₀W₀) 3.338
Direct band gap (G₀W₀) 3.367
Valence band maximum wrt. vacuum (G₀W₀) -7.485
Conduction band minimum wrt. vacuum (G₀W₀) -4.147

VBM
Property (VBM) Value
Min eff. mass 0.38 m0
Max eff. mass 1.19 m0
DOS eff. mass 0.67 m0
Crystal coordinates [0.120, 0.120]
Warping parameter -0.000
Barrier height > 47.6 meV
Distance to barrier > 0.0216 Å-1
CBM
Property (CBM) Value
Min eff. mass 0.40 m0
Max eff. mass 0.40 m0
DOS eff. mass 0.40 m0
Crystal coordinates [0.000, 0.000]
Warping parameter 0.003
Barrier height > 120.0 meV
Distance to barrier > 0.0214 Å-1

ZPbij ux uy uz
Px 3.27 -0.00 0.00
Py -0.00 3.27 -0.00
Pz -0.00 0.00 0.63
ZIij ux uy uz
Px -1.63 0.00 0.00
Py 0.00 -1.63 -0.00
Pz 0.00 -0.00 -0.32
ZIij ux uy uz
Px -1.63 -0.00 -0.00
Py 0.00 -1.63 0.00
Pz 0.00 0.00 -0.32

Atom No. Chemical symbol Charges [|e|]
0 Pb 0.92
1 I -0.46
2 I -0.46

AB2/1PbI2/2/rpa-pol-x.png AB2/1PbI2/2/rpa-pol-z.png
AB2/1PbI2/2/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 2.598
Interband polarizability (y) [Å] 2.598
Interband polarizability (z) [Å] 0.461
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000

AB2/1PbI2/2/ir-pol-x.png AB2/1PbI2/2/ir-pol-z.png
AB2/1PbI2/2/ir-pol-y.png
Static polarizability [Å]
Phonons only (x) 5.27
Phonons only (y) 5.26
Phonons only (z) 0.05
Total (phonons + electrons) (x) 7.87
Total (phonons + electrons) (y) 7.86
Total (phonons + electrons) (z) 0.51

AB2/1PbI2/2/absx.png
Exciton binding energy (BSE) [eV] 0.76
AB2/1PbI2/2/absz.png

AB2/1PbI2/2/shg1.png
Element Relations
yyy yyy=-xxy=-yxx=-xyx
Others 0=xxx=xxz=xyy=xyz=xzx=xzy=xzz=yxy=yxz=yyx=yyz=yzx= yzy=yzz=zxx=zxy=zxz=zyx=zyy=zyz=zzx=zzy=zzz
AB2/1PbI2/2/shg2.png

Shift-current
Element Relations
yyy yyy=-xyx=-yxx=-xxy
Others 0=xxx=xxz=xyy=xyz=xzx=xzy=xzz=yxy=yxz=yyx=yyz=yzx= yzy=yzz=zxx=zxy=zxz=zyx=zyy=zyz=zzx=zzy=zzz

Miscellaneous details
Unique ID 1PbI2-2
Number of atoms 3
Number of species 2
Formula PbI2
Reduced formula PbI2
Stoichiometry AB2
Unit cell area [Å2] 17.556
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/AB2/PbI2/PbI2-9e6494406d07
Old uid PbI2-9e6494406d07
Space group (bulk in AA-stacking) P-6m2
Space group number (bulk in AA-stacking) 187
Point group -6m2
Inversion symmetry No
Layer group number 78
Layer group p-6m2
2D Bravais type Hexagonal (hp)
Thickness [Å] 4.062
Structure origin original03-18
Band gap (PBE) [eV] 1.577
Direct band gap (PBE) [eV] 1.628
gap_dir_nosoc 2.904
Vacuum level [eV] 3.352
Fermi level wrt. vacuum (PBE) [eV] -5.452
Valence band maximum wrt. vacuum (PBE) [eV] -6.240
Conduction band minimum wrt. vacuum (PBE) [eV] -4.663
minhessianeig -0.000
Dynamically stable Yes
Band gap (HSE06) [eV] 2.404
Miscellaneous details
Direct band gap (HSE06) [eV] 2.543
Fermi level wrt. vacuum (HSE) [eV] -5.380
Valence band maximum wrt. vacuum (HSE06) [eV] -6.737
Conduction band minimum wrt. vacuum (HSE06) [eV] -4.333
Band gap (G₀W₀) [eV] 3.338
Direct band gap (G₀W₀) [eV] 3.367
Fermi level wrt. vacuum (G₀W₀) [eV] -5.260
Valence band maximum wrt. vacuum (G₀W₀) [eV] -7.485
Conduction band minimum wrt. vacuum (G₀W₀) [eV] -4.147
E_B 0.762
Interband polarizability (x) [Å] 2.598
Interband polarizability (y) [Å] 2.598
Interband polarizability (z) [Å] 0.461
Static polarizability (phonons) (x) [Å] 5.273
Static polarizability (phonons + electrons) (x) [Å] 7.871
Static polarizability (phonons) (y) [Å] 5.264
Static polarizability (phonons + electrons) (y) [Å] 7.862
Static polarizability (phonons) (z) [Å] 0.053
Static polarizability (phonons + electrons) (z) [Å] 0.514
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000
Energy [eV] -8.559
Magnetic No
Spin axis z
Magnetic anisotropy energy, xz [meV/unit cell] 0.000
Magnetic anisotropy energy, yz [meV/unit cell] 0.000
Energy above convex hull [eV/atom] 0.078
Heat of formation [eV/atom] -0.614