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Structure info
Layer group p2_122
Layer group number 20
Structure origin original03-18
Stability
Energy above convex hull [eV/atom] 0.000
Heat of formation [eV/atom] -0.143
Dynamically stable Yes
Basic properties
Magnetic No
Band gap (PBE) [eV] 0.791
Band gap (HSE06) [eV] 2.099
XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 5.071 0.000 0.000 Yes
2 0.000 7.967 0.000 Yes
3 0.000 0.000 18.170 No
Lengths [Å] 5.071 7.967 18.170
Angles [°] 90.000 90.000 90.000

Symmetries
2D Bravais type Rectangular (op)
Layer group number 20
Layer group p2_122
Space group number (bulk in AA-stacking) 17
Space group (bulk in AA-stacking) P222_1
Point group 222
Inversion symmetry No
Structure data
Formula Cu2I2Se4
Stoichiometry ABC2
Number of atoms 8
Unit cell area [Å2] 40.397
Thickness [Å] 3.559

Cu2I2Se4 (2CuISe2-1)
Heat of formation [eV/atom] -0.14
Energy above convex hull [eV/atom] 0.00
Monolayers from C2DB
Cu2I2 (2CuI-1) -0.17 eV/atom
Cu2I2 (2CuI-2) -0.16 eV/atom
Cu3I3 (3CuI-1) -0.15 eV/atom
Cu4I4Se4 (4CuISe-1) -0.15 eV/atom
Cu2I2Se4, (2CuISe2-1) -0.14 eV/atom
Cu5I5 (5CuI-1) -0.14 eV/atom
Cu6I6 (6CuI-1) -0.14 eV/atom
Cu4I4 (4CuI-1) -0.13 eV/atom
CuI2 (1CuI2-1) -0.13 eV/atom
Cu2I3 (1Cu2I3-1) -0.12 eV/atom
Cu4I6 (2Cu2I3-1) -0.12 eV/atom
Se2Cu3 (1Se2Cu3-1) -0.11 eV/atom
Se2Cu4 (2SeCu2-1) -0.11 eV/atom
Cu3I6 (3CuI2-1) -0.11 eV/atom
Cu9I11 (1Cu9I11-1) -0.10 eV/atom
Cu6I6 (6CuI-2) -0.10 eV/atom
Cu3I3 (3CuI-2) -0.10 eV/atom
Cu6I6 (6CuI-3) -0.10 eV/atom
Cu3I3 (3CuI-3) -0.10 eV/atom
Cu3I3 (3CuI-4) -0.09 eV/atom
Cu2I4 (2CuI2-1) -0.09 eV/atom
SeCu2I2 (1SeCu2I2-1) -0.09 eV/atom
Cu3I5 (1Cu3I5-1) -0.09 eV/atom
Cu2Se2 (2CuSe-1) -0.09 eV/atom
Cu4I4 (4CuI-2) -0.09 eV/atom
CuI (1CuI-1) -0.08 eV/atom
Cu2Se2 (2CuSe-2) -0.08 eV/atom
Cu4I8 (4CuI2-1) -0.08 eV/atom
Cu4I8 (4CuI2-2) -0.08 eV/atom
Cu3I4 (1Cu3I4-1) -0.07 eV/atom
Cu2Se2 (2CuSe-3) -0.07 eV/atom
Se5Cu6 (1Se5Cu6-1) -0.07 eV/atom
Cu2I4 (2CuI2-2) -0.06 eV/atom
Cu4I6 (2Cu2I3-2) -0.05 eV/atom
CuI2 (1CuI2-2) -0.05 eV/atom
Se2Cu4 (2SeCu2-2) -0.04 eV/atom
Cu2Se2 (2CuSe-4) -0.04 eV/atom
Cu2I5 (1Cu2I5-1) -0.03 eV/atom
Cu2I2Se2 (2CuISe-1) -0.00 eV/atom
Cu2Se4 (2CuSe2-1) -0.00 eV/atom
Cu2Se2 (2CuSe-5) 0.02 eV/atom
CuSe2 (1CuSe2-1) 0.03 eV/atom
Cu2I6 (2CuI3-1) 0.05 eV/atom
CuI2 (1CuI2-3) 0.09 eV/atom
Cu2Se4 (2CuSe2-2) 0.10 eV/atom
Cu2I6 (2CuI3-2) 0.10 eV/atom
CuSe2 (1CuSe2-2) 0.12 eV/atom
Cu2Se2 (2CuSe-6) 0.12 eV/atom
SeCu2 (1SeCu2-1) 0.14 eV/atom
CuSe2 (1CuSe2-3) 0.17 eV/atom
Se2 (2Se-1) 0.21 eV/atom
Se2 (2Se-2) 0.29 eV/atom
Bulk crystals from OQMD123
CuI -0.16 eV/atom
Cu6Se4 -0.15 eV/atom
Cu6Se6 -0.14 eV/atom
Cu6I6Se18 -0.11 eV/atom
Cu2Se4 -0.10 eV/atom
Cu 0.00 eV/atom
I4 0.00 eV/atom
Se3 0.00 eV/atom

ABC2/2CuISe2/1/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

DVB [eV] xx yy xy
Γ -0.56 1.38 -0.00
X -1.14 -0.44 -0.00
S -0.84 -1.21 -0.00
Y -1.74 -2.94 -0.00
kVBM -1.69 -2.93 -0.00
xx yy xy
Band gap [eV] 0.37 2.17 0.00
DCB [eV] xx yy xy
Γ -1.31 -0.76 0.00
X -3.16 -2.66 0.01
S -3.02 -2.22 0.00
Y -4.52 -3.25 0.00
kCBM -1.31 -0.76 0.00

Cij (N/m) xx yy xy
xx 15.56 5.73 -0.02
yy 7.13 21.26 -0.06
xy 0.00 -0.01 21.00
Stiffness tensor eigenvalues
Eigenvalue 0 11.41 N/m
Eigenvalue 1 21.00 N/m
Eigenvalue 2 25.41 N/m

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

Key values [eV]
Band gap (PBE) 0.791
Direct band gap (PBE) 0.912
Valence band maximum wrt. vacuum (PBE) -5.434
Conduction band minimum wrt. vacuum (PBE) -4.643
DOS BZ

Key values [eV]
Band gap (HSE06) 2.099
Direct band gap (HSE06) 2.111
Valence band maximum wrt. vacuum (HSE06) -6.721
Conduction band minimum wrt. vacuum (HSE06) -4.621

VBM
Property (VBM) Value
Min eff. mass 0.68 m0
Max eff. mass 2.05 m0
DOS eff. mass 1.18 m0
Crystal coordinates [0.065, 0.500]
Warping parameter -0.001
Barrier height > 14.4 meV
Distance to barrier > 0.0172 Å-1
CBM
Property (CBM) Value
Min eff. mass 0.74 m0
Max eff. mass 1.03 m0
DOS eff. mass 0.88 m0
Crystal coordinates [0.000, 0.030]
Warping parameter 0.001
Barrier height 2.2 meV
Distance to barrier 0.004 Å-1

ZIij ux uy uz
Px -1.29 0.19 0.00
Py -0.12 -1.94 -0.00
Pz -0.00 -0.00 -0.28
ZSeij ux uy uz
Px 0.52 0.18 -0.40
Py 0.26 0.47 0.48
Pz -0.01 0.02 0.02
ZSeij ux uy uz
Px 0.54 -0.22 -0.41
Py -0.29 0.51 -0.47
Pz -0.01 -0.02 0.02
ZCuij ux uy uz
Px 0.24 0.00 -1.01
Py 0.00 0.97 -0.01
Pz -0.13 -0.00 0.23
ZIij ux uy uz
Px -1.29 -0.19 -0.00
Py 0.12 -1.95 -0.00
Pz 0.00 -0.00 -0.28
ZSeij ux uy uz
Px 0.52 -0.18 0.40
Py -0.26 0.47 0.48
Pz 0.01 0.02 0.02
ZSeij ux uy uz
Px 0.54 0.22 0.41
Py 0.29 0.50 -0.47
Pz 0.01 -0.02 0.02
ZCuij ux uy uz
Px 0.24 -0.00 1.01
Py -0.00 0.97 -0.01
Pz 0.13 -0.00 0.23

Atom No. Chemical symbol Charges [|e|]
0 I -0.38
1 I -0.38
2 Se 0.01
3 Se 0.01
4 Se 0.01
5 Se 0.01
6 Cu 0.37
7 Cu 0.37

ABC2/2CuISe2/1/rpa-pol-x.png ABC2/2CuISe2/1/rpa-pol-z.png
ABC2/2CuISe2/1/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 3.487
Interband polarizability (y) [Å] 4.046
Interband polarizability (z) [Å] 0.364
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000

ABC2/2CuISe2/1/ir-pol-x.png ABC2/2CuISe2/1/ir-pol-z.png
ABC2/2CuISe2/1/ir-pol-y.png
Static polarizability [Å]
Phonons only (x) 1.96
Phonons only (y) 1.75
Phonons only (z) 0.02
Total (phonons + electrons) (x) 5.45
Total (phonons + electrons) (y) 5.79
Total (phonons + electrons) (z) 0.38

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

Miscellaneous details
Unique ID 2CuISe2-1
Number of atoms 8
Number of species 3
Formula Cu2I2Se4
Reduced formula CuISe2
Stoichiometry ABC2
Unit cell area [Å2] 40.397
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/ABC2/CuISe2/Cu2I2Se4-b30d27347163
Old uid Cu2I2Se4-b30d27347163
Space group (bulk in AA-stacking) P222_1
Space group number (bulk in AA-stacking) 17
Point group 222
Inversion symmetry No
Layer group number 20
Layer group p2_122
2D Bravais type Rectangular (op)
Thickness [Å] 3.559
Structure origin original03-18
Band gap (PBE) [eV] 0.791
Direct band gap (PBE) [eV] 0.912
gap_dir_nosoc 0.984
Vacuum level [eV] 2.849
Fermi level wrt. vacuum (PBE) [eV] -5.038
Valence band maximum wrt. vacuum (PBE) [eV] -5.434
Conduction band minimum wrt. vacuum (PBE) [eV] -4.643
Miscellaneous details
minhessianeig -0.000
Dynamically stable Yes
Band gap (HSE06) [eV] 2.099
Direct band gap (HSE06) [eV] 2.111
Fermi level wrt. vacuum (HSE) [eV] -5.652
Valence band maximum wrt. vacuum (HSE06) [eV] -6.721
Conduction band minimum wrt. vacuum (HSE06) [eV] -4.621
Interband polarizability (x) [Å] 3.487
Interband polarizability (y) [Å] 4.046
Interband polarizability (z) [Å] 0.364
Static polarizability (phonons) (x) [Å] 1.960
Static polarizability (phonons + electrons) (x) [Å] 5.446
Static polarizability (phonons) (y) [Å] 1.749
Static polarizability (phonons + electrons) (y) [Å] 5.795
Static polarizability (phonons) (z) [Å] 0.016
Static polarizability (phonons + electrons) (z) [Å] 0.380
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000
Energy [eV] -25.386
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] -0.143