Structure info
Layer group p4/nmm
Layer group number 64
Structure origin exfoliated02-21
ICSD id of parent bulk structure ICSD 162904
Stability
Energy above convex hull [eV/atom] 0.069
Heat of formation [eV/atom] -0.072
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 3.712 -0.000 0.000 Yes
2 -0.000 3.712 0.000 Yes
3 0.000 0.000 33.033 No
Lengths [Å] 3.712 3.712 33.033
Angles [°] 90.000 90.000 90.000

Symmetries
2D Bravais type Square (tp)
Layer group number 64
Layer group p4/nmm
Space group number (bulk in AA-stacking) 129
Space group (bulk in AA-stacking) P4/nmm
Point group 4/mmm
Inversion symmetry Yes
Structure data
Formula Cu2Se2
Stoichiometry AB
Number of atoms 4
Unit cell area [Å2] 13.780
Thickness [Å] 3.199

Cu2Se2 (2CuSe-3)
Heat of formation [eV/atom] -0.07
Energy above convex hull [eV/atom] 0.07
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/3/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

Cij (N/m) xx yy xy
xx 33.36 16.76 -0.00
yy 16.72 33.41 -0.00
xy 0.00 0.00 34.00
Stiffness tensor eigenvalues
Eigenvalue 0 16.65 N/m
Eigenvalue 1 34.00 N/m
Eigenvalue 2 50.12 N/m

Key values [eV]
Band gap (PBE) 0.000
Direct band gap (PBE) 0.000
Fermi level wrt. vacuum (PBE) -5.665
DOS BZ

AB/2CuSe/3/fermi_surface.png

Atom No. Chemical symbol Charges [|e|]
0 Cu 0.36
1 Cu 0.36
2 Se -0.36
3 Se -0.36

AB/2CuSe/3/rpa-pol-x.png AB/2CuSe/3/rpa-pol-z.png
AB/2CuSe/3/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 13.287
Interband polarizability (y) [Å] 13.287
Interband polarizability (z) [Å] 0.429
Plasma frequency (x) [eV Å0.5] 7.990
Plasma frequency (y) [eV Å0.5] 7.990

Miscellaneous details
Unique ID 2CuSe-3
Number of atoms 4
Number of species 2
Formula Cu2Se2
Reduced formula CuSe
Stoichiometry AB
Unit cell area [Å2] 13.780
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/ICSD-COD/2el/Cu2Se2
Old uid Cu2Se2-fd100f434576
Space group (bulk in AA-stacking) P4/nmm
Space group number (bulk in AA-stacking) 129
Point group 4/mmm
Inversion symmetry Yes
Layer group number 64
Layer group p4/nmm
2D Bravais type Square (tp)
Thickness [Å] 3.199
Structure origin exfoliated02-21
Band gap (PBE) [eV] 0.000
Miscellaneous details
Direct band gap (PBE) [eV] 0.000
gap_dir_nosoc 0.000
Vacuum level [eV] 1.849
Fermi level wrt. vacuum (PBE) [eV] -5.665
minhessianeig -0.000
Dynamically stable Yes
Interband polarizability (x) [Å] 13.287
Interband polarizability (y) [Å] 13.287
Interband polarizability (z) [Å] 0.429
Plasma frequency (x) [eV Å0.5] 7.990
Plasma frequency (y) [eV Å0.5] 7.990
Energy [eV] -14.606
ICSD id of parent bulk structure ICSD 162904
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] 0.069
Heat of formation [eV/atom] -0.072