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Structure info
Layer group p-6m2
Layer group number 78
Structure origin original03-18
COD id of parent bulk structure COD 9008967
ICSD id of parent bulk structure ICSD 640503
Mono/few-layer report(s) 10.1088/2053-1583/aab390
Stability
Energy above convex hull [eV/atom] 0.000
Heat of formation [eV/atom] -0.538
Dynamically stable Yes
Basic properties
Magnetic No
Band gap (PBE) [eV] 1.404
Band gap (HSE06) [eV] 2.055
Band gap (G₀W₀) [eV] 2.740
XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 4.074 -0.000 0.000 Yes
2 -2.037 3.528 0.000 Yes
3 0.000 0.000 20.367 No
Lengths [Å] 4.074 4.074 20.367
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 In2Se2
Stoichiometry AB
Number of atoms 4
Unit cell area [Å2] 14.376
Thickness [Å] 5.367

In2Se2 (2InSe-1)
Heat of formation [eV/atom] -0.54
Energy above convex hull [eV/atom] 0.00
Monolayers from C2DB
In2Se2, (2InSe-1) -0.54 eV/atom
In2Se2 (2InSe-2) -0.53 eV/atom
In4Se6 (2In2Se3-1) -0.53 eV/atom
In2Se3 (1In2Se3-1) -0.53 eV/atom
In8Se12 (4In2Se3-1) -0.51 eV/atom
In3Se4 (1In3Se4-1) -0.51 eV/atom
In2Se2 (2InSe-3) -0.50 eV/atom
In2Se3 (1In2Se3-2) -0.50 eV/atom
Se12In13 (1Se12In13-1) -0.49 eV/atom
In2Se3 (1In2Se3-3) -0.48 eV/atom
Se12In14 (2Se6In7-1) -0.44 eV/atom
Se12In15 (3Se4In5-1) -0.42 eV/atom
In2Se2 (2InSe-4) -0.39 eV/atom
In2Se5 (1In2Se5-1) -0.36 eV/atom
In2Se2 (2InSe-5) -0.29 eV/atom
In2Se2 (2InSe-6) -0.23 eV/atom
In2Se4 (2InSe2-1) -0.22 eV/atom
InSe2 (1InSe2-1) -0.21 eV/atom
In2Se3 (1In2Se3-4) -0.16 eV/atom
In2Se4 (2InSe2-2) -0.16 eV/atom
In2Se4 (2InSe2-3) -0.11 eV/atom
In2Se4 (2InSe2-4) -0.04 eV/atom
InSe4 (1InSe4-1) 0.04 eV/atom
Se2 (2Se-1) 0.21 eV/atom
Se2 (2Se-2) 0.29 eV/atom
Bulk crystals from OQMD123
In4Se4 -0.53 eV/atom
In12Se18 -0.53 eV/atom
In 0.00 eV/atom
Se3 0.00 eV/atom

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

DVB [eV] xx yy xy
Γ 1.81 1.81 0.00
M 1.03 2.62 -1.28
K 1.36 1.40 0.00
kVBM 2.41 2.09 -0.27
xx yy xy
Band gap [eV] -8.38 -8.07 0.27
DCB [eV] xx yy xy
Γ -5.98 -5.98 0.00
M -0.24 -3.82 3.06
K 2.91 2.93 0.00
kCBM -5.98 -5.98 0.00

Cij (N/m) xx yy xy
xx 51.61 15.95 0.00
yy 15.52 51.32 0.00
xy 0.00 0.00 36.87
Stiffness tensor eigenvalues
Eigenvalue 0 35.74 N/m
Eigenvalue 1 36.87 N/m
Eigenvalue 2 67.20 N/m

cij [e/Å] xx yy xy
x -0.00 -0.00 -0.04
y -0.02 0.01 0.00
z 0.00 0.00 0.00
cijclamped [e/Å] xx yy xy
x -0.00 -0.00 -0.31
y -0.31 0.31 -0.00
z -0.00 0.00 0.00

Key values [eV]
Band gap (PBE) 1.404
Direct band gap (PBE) 1.448
Valence band maximum wrt. vacuum (PBE) -5.912
Conduction band minimum wrt. vacuum (PBE) -4.507
DOS BZ

Key values [eV]
Band gap (HSE06) 2.055
Direct band gap (HSE06) 2.097
Valence band maximum wrt. vacuum (HSE06) -6.369
Conduction band minimum wrt. vacuum (HSE06) -4.313

Key values [eV]
Band gap (G₀W₀) 2.740
Direct band gap (G₀W₀) 2.775
Valence band maximum wrt. vacuum (G₀W₀) -6.970
Conduction band minimum wrt. vacuum (G₀W₀) -4.230

VBM
Property (VBM) Value
Min eff. mass 2.57 m0
Max eff. mass 11.35 m0
DOS eff. mass 5.11 m0
Crystal coordinates [0.080, 0.080]
Warping parameter -0.020
Barrier height > 4.9 meV
Distance to barrier > 0.0179 Å-1
CBM
Property (CBM) Value
Min eff. mass 0.20 m0
Max eff. mass 0.20 m0
DOS eff. mass 0.20 m0
Crystal coordinates [0.000, 0.000]
Warping parameter 0.000
Barrier height > 227.8 meV
Distance to barrier > 0.0177 Å-1

ZInij ux uy uz
Px 2.42 0.00 -0.00
Py -0.00 2.42 0.00
Pz -0.00 0.00 0.26
ZSeij ux uy uz
Px -2.42 -0.00 0.00
Py -0.00 -2.42 -0.00
Pz 0.00 0.00 -0.26
ZInij ux uy uz
Px 2.42 0.00 0.00
Py -0.00 2.42 -0.00
Pz 0.00 0.00 0.26
ZSeij ux uy uz
Px -2.42 -0.00 -0.00
Py 0.00 -2.42 0.00
Pz 0.00 -0.00 -0.26

Atom No. Chemical symbol Charges [|e|]
0 In 0.66
1 In 0.71
2 Se -0.68
3 Se -0.68

AB/2InSe/1/rpa-pol-x.png AB/2InSe/1/rpa-pol-z.png
AB/2InSe/1/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 4.235
Interband polarizability (y) [Å] 4.235
Interband polarizability (z) [Å] 0.561
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000

AB/2InSe/1/ir-pol-x.png AB/2InSe/1/ir-pol-z.png
AB/2InSe/1/ir-pol-y.png
Static polarizability [Å]
Phonons only (x) 2.50
Phonons only (y) 2.50
Phonons only (z) 0.02
Total (phonons + electrons) (x) 6.74
Total (phonons + electrons) (y) 6.73
Total (phonons + electrons) (z) 0.58

AB/2InSe/1/absx.png
Exciton binding energy (BSE) [eV] 0.67
AB/2InSe/1/absz.png

AB/2InSe/1/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
AB/2InSe/1/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 2InSe-1
Number of atoms 4
Number of species 2
Formula In2Se2
Reduced formula InSe
Stoichiometry AB
Unit cell area [Å2] 14.376
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/AB/InSe/In2Se2-eb204c739879
Old uid In2Se2-eb204c739879
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] 5.367
Structure origin original03-18
Band gap (PBE) [eV] 1.404
Direct band gap (PBE) [eV] 1.448
gap_dir_nosoc 1.501
Vacuum level [eV] 3.968
Fermi level wrt. vacuum (PBE) [eV] -5.209
Valence band maximum wrt. vacuum (PBE) [eV] -5.912
Conduction band minimum wrt. vacuum (PBE) [eV] -4.507
minhessianeig -0.000
Dynamically stable Yes
Band gap (HSE06) [eV] 2.055
Direct band gap (HSE06) [eV] 2.097
Fermi level wrt. vacuum (HSE) [eV] -5.243
Miscellaneous details
Valence band maximum wrt. vacuum (HSE06) [eV] -6.369
Conduction band minimum wrt. vacuum (HSE06) [eV] -4.313
Band gap (G₀W₀) [eV] 2.740
Direct band gap (G₀W₀) [eV] 2.775
Fermi level wrt. vacuum (G₀W₀) [eV] -5.600
Valence band maximum wrt. vacuum (G₀W₀) [eV] -6.970
Conduction band minimum wrt. vacuum (G₀W₀) [eV] -4.230
E_B 0.667
Interband polarizability (x) [Å] 4.235
Interband polarizability (y) [Å] 4.235
Interband polarizability (z) [Å] 0.561
Static polarizability (phonons) (x) [Å] 2.500
Static polarizability (phonons + electrons) (x) [Å] 6.735
Static polarizability (phonons) (y) [Å] 2.500
Static polarizability (phonons + electrons) (y) [Å] 6.735
Static polarizability (phonons) (z) [Å] 0.022
Static polarizability (phonons + electrons) (z) [Å] 0.584
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000
Energy [eV] -14.642
ICSD id of parent bulk structure ICSD 640503
COD id of parent bulk structure COD 9008967
Mono/few-layer report(s) 10.1088/2053-1583/aab390
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] 0.000
Heat of formation [eV/atom] -0.538