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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] 0.552
Heat of formation [eV/atom] -1.529
Dynamically stable No
Basic properties
Magnetic No
Band gap (PBE) [eV] 0.000
  XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 3.151 -0.000 0.000 Yes
2 -1.576 2.729 0.000 Yes
3 0.000 0.000 19.471 No
Lengths [Å] 3.151 3.151 19.471
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 Nb2O2
Stoichiometry AB
Number of atoms 4
Unit cell area [Å2] 8.600
Thickness [Å] 4.489

Nb2O2 (2NbO-1)
Heat of formation [eV/atom] -1.53
Energy above convex hull [eV/atom] 0.55
Monolayers from C2DB
Nb4O8 (4NbO2-1) -2.42 eV/atom
Nb2O4 (2NbO2-1) -2.38 eV/atom
NbO2 (1NbO2-1) -2.37 eV/atom
NbO2 (1NbO2-2) -2.35 eV/atom
NbO2 (1NbO2-3) -2.20 eV/atom
Nb2O6 (2NbO3-1) -2.07 eV/atom
Nb4O12 (4NbO3-1) -1.83 eV/atom
Nb2O2, (2NbO-1) -1.53 eV/atom
Nb2O2 (2NbO-2) -1.30 eV/atom
Nb2O2 (2NbO-3) -1.02 eV/atom
Bulk crystals from OQMD123
Nb2O5 -2.77 eV/atom
Nb8O16 -2.64 eV/atom
Nb3O3 -2.08 eV/atom
Nb 0.00 eV/atom
O8 0.00 eV/atom

AB/2NbO/1/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -6.98

Cij (N/m) xx yy xy
xx -264.96 433.23 -0.89
yy 430.24 -266.06 4.50
xy 0.00 0.00 -738.87
Stiffness tensor eigenvalues
Eigenvalue 0 -738.87 N/m
Eigenvalue 1 -697.24 N/m
Eigenvalue 2 166.22 N/m

Key values [eV]
Band gap (PBE) 0.000
Direct band gap (PBE) 0.000
Fermi level wrt. vacuum (PBE) -4.754
DOS BZ

AB/2NbO/1/fermi_surface.png

Atom No. Chemical symbol Charges [|e|]
0 Nb 1.17
1 Nb 1.23
2 O -1.20
3 O -1.20

AB/2NbO/1/rpa-pol-x.png AB/2NbO/1/rpa-pol-z.png
AB/2NbO/1/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 22.437
Interband polarizability (y) [Å] 22.437
Interband polarizability (z) [Å] 0.970
Plasma frequency (x) [eV Å0.5] 7.267
Plasma frequency (y) [eV Å0.5] 7.267

Miscellaneous details
Unique ID 2NbO-1
Number of atoms 4
Number of species 2
Formula Nb2O2
Reduced formula NbO
Stoichiometry AB
Unit cell area [Å2] 8.600
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/AB/NbO/Nb2O2-b9c0d505df57
Old uid Nb2O2-b9c0d505df57
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] 4.489
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] 4.721
Fermi level wrt. vacuum (PBE) [eV] -4.754
minhessianeig -6.983
Dynamically stable No
Interband polarizability (x) [Å] 22.437
Interband polarizability (y) [Å] 22.437
Interband polarizability (z) [Å] 0.970
Plasma frequency (x) [eV Å0.5] 7.267
Plasma frequency (y) [eV Å0.5] 7.267
Energy [eV] -37.016
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] 0.552
Heat of formation [eV/atom] -1.529