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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] 0.158
Heat of formation [eV/atom] 0.017
Dynamically stable Yes
Basic properties
Magnetic No
Band gap (PBE) [eV] 0.000
XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 4.093 0.000 0.000 Yes
2 -2.047 3.545 0.000 Yes
3 0.000 0.000 17.781 No
Lengths [Å] 4.093 4.093 17.781
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 Cu2Se2
Stoichiometry AB
Number of atoms 4
Unit cell area [Å2] 14.511
Thickness [Å] 2.736

Cu2Se2 (2CuSe-5)
Heat of formation [eV/atom] 0.02
Energy above convex hull [eV/atom] 0.16
Monolayers from C2DB
Se2Cu3 (1Se2Cu3-1) -0.11 eV/atom
Se2Cu4 (2SeCu2-1) -0.11 eV/atom
Cu2Se2 (2CuSe-1) -0.09 eV/atom
Cu2Se2 (2CuSe-2) -0.08 eV/atom
Cu2Se2 (2CuSe-3) -0.07 eV/atom
Se5Cu6 (1Se5Cu6-1) -0.07 eV/atom
Se2Cu4 (2SeCu2-2) -0.04 eV/atom
Cu2Se2 (2CuSe-4) -0.04 eV/atom
Cu2Se4 (2CuSe2-1) -0.00 eV/atom
Cu2Se2, (2CuSe-5) 0.02 eV/atom
CuSe2 (1CuSe2-1) 0.03 eV/atom
Cu2Se4 (2CuSe2-2) 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
Cu6Se4 -0.15 eV/atom
Cu6Se6 -0.14 eV/atom
Cu2Se4 -0.10 eV/atom
Cu 0.00 eV/atom
Se3 0.00 eV/atom

AB/2CuSe/5/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

Cij (N/m) xx yy xy
xx 67.98 41.11 0.00
yy 41.61 67.93 0.00
xy -0.00 -0.00 26.82
Stiffness tensor eigenvalues
Eigenvalue 0 26.60 N/m
Eigenvalue 1 26.82 N/m
Eigenvalue 2 109.32 N/m

Key values [eV]
Band gap (PBE) 0.000
Direct band gap (PBE) 0.000
Fermi level wrt. vacuum (PBE) -4.179
DOS BZ

AB/2CuSe/5/fermi_surface.png

Atom No. Chemical symbol Charges [|e|]
0 Cu 0.32
1 Cu 0.34
2 Se -0.35
3 Se -0.31

AB/2CuSe/5/rpa-pol-x.png AB/2CuSe/5/rpa-pol-z.png
AB/2CuSe/5/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 91.038
Interband polarizability (y) [Å] 91.038
Interband polarizability (z) [Å] 0.422
Plasma frequency (x) [eV Å0.5] 4.528
Plasma frequency (y) [eV Å0.5] 4.528

AB/2CuSe/5/Raman.png
Mode Frequency (1/cm) Degeneracy
Mode 1 0. 3
Mode 2 33.1 2
Mode 3 95.4 1
Mode 4 115.7 1
Mode 5 163.4 1
Mode 6 220.7 2
Mode 7 227. 2

Miscellaneous details
Unique ID 2CuSe-5
Number of atoms 4
Number of species 2
Formula Cu2Se2
Reduced formula CuSe
Stoichiometry AB
Unit cell area [Å2] 14.511
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/AB/CuSe/Cu2Se2-6338a036fe4f
Old uid Cu2Se2-6338a036fe4f
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] 2.736
Structure origin original03-18
Band gap (PBE) [eV] 0.000
Miscellaneous details
Direct band gap (PBE) [eV] 0.000
gap_dir_nosoc 0.000
Vacuum level [eV] 3.105
Fermi level wrt. vacuum (PBE) [eV] -4.179
minhessianeig -0.000
Dynamically stable Yes
Interband polarizability (x) [Å] 91.038
Interband polarizability (y) [Å] 91.038
Interband polarizability (z) [Å] 0.422
Plasma frequency (x) [eV Å0.5] 4.528
Plasma frequency (y) [eV Å0.5] 4.528
Energy [eV] -14.251
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] 0.158
Heat of formation [eV/atom] 0.017