Structure info
Layer group p-6m2
Layer group number 78
Structure origin original03-18
Stability
Energy above convex hull [eV/atom] 0.555
Heat of formation [eV/atom] -0.122
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 3.197 -0.000 0.000 Yes
2 -1.599 2.769 0.000 Yes
3 0.000 0.000 21.405 No
Lengths [Å] 3.197 3.197 21.405
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 Ta2Se2
Stoichiometry AB
Number of atoms 4
Unit cell area [Å2] 8.853
Thickness [Å] 6.406

Se2Ta2 (2SeTa-5)
Heat of formation [eV/atom] -0.12
Energy above convex hull [eV/atom] 0.55
Monolayers from C2DB
TaSe2 (1TaSe2-1) -0.84 eV/atom
TaSe2 (1TaSe2-2) -0.81 eV/atom
Ta4Se6 (2Ta2Se3-1) -0.79 eV/atom
Ta7Se12 (1Ta7Se12-1) -0.77 eV/atom
Ta4Se12 (4TaSe3-1) -0.68 eV/atom
Ta8Se12 (4Ta2Se3-1) -0.66 eV/atom
Ta2Se6 (2TaSe3-1) -0.63 eV/atom
Ta9Se12 (3Ta3Se4-1) -0.56 eV/atom
Se2Ta4 (2SeTa2-1) -0.49 eV/atom
Se2Ta2 (2SeTa-1) -0.38 eV/atom
TaSe2 (1TaSe2-3) -0.37 eV/atom
Se2Ta2 (2SeTa-2) -0.34 eV/atom
Se2Ta2 (2SeTa-3) -0.30 eV/atom
Se2Ta2 (2SeTa-4) -0.13 eV/atom
Se2Ta2, (2SeTa-5) -0.12 eV/atom
Se2 (2Se-1) 0.21 eV/atom
Se2 (2Se-2) 0.29 eV/atom
Bulk crystals from OQMD123
Se2Ta -0.84 eV/atom
Se12Ta4 -0.68 eV/atom
Se2Ta4 -0.46 eV/atom
Se3 0.00 eV/atom
Ta 0.00 eV/atom

AB/2SeTa/5/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -1.96

Cij (N/m) xx yy xy
xx 148.55 10.75 0.00
yy 10.75 148.35 0.00
xy 0.00 0.00 138.81
Stiffness tensor eigenvalues
Eigenvalue 0 137.70 N/m
Eigenvalue 1 138.81 N/m
Eigenvalue 2 159.20 N/m

Key values [eV]
Band gap (PBE) 0.000
Direct band gap (PBE) 0.000
Fermi level wrt. vacuum (PBE) -5.152
DOS BZ

AB/2SeTa/5/fermi_surface.png

Atom No. Chemical symbol Charges [|e|]
0 Ta 0.63
1 Ta 0.68
2 Se -0.66
3 Se -0.66

AB/2SeTa/5/rpa-pol-x.png AB/2SeTa/5/rpa-pol-z.png
AB/2SeTa/5/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 22.729
Interband polarizability (y) [Å] 22.729
Interband polarizability (z) [Å] 0.730
Plasma frequency (x) [eV Å0.5] 6.648
Plasma frequency (y) [eV Å0.5] 6.648

Miscellaneous details
Unique ID 2SeTa-5
Number of atoms 4
Number of species 2
Formula Ta2Se2
Reduced formula TaSe
Stoichiometry AB
Unit cell area [Å2] 8.853
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/AB/SeTa/Se2Ta2-d1a2e3b69ba5
Old uid Se2Ta2-d1a2e3b69ba5
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] 6.406
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] 6.079
Fermi level wrt. vacuum (PBE) [eV] -5.152
minhessianeig -1.956
Dynamically stable No
Interband polarizability (x) [Å] 22.729
Interband polarizability (y) [Å] 22.729
Interband polarizability (z) [Å] 0.730
Plasma frequency (x) [eV Å0.5] 6.648
Plasma frequency (y) [eV Å0.5] 6.648
Energy [eV] -27.086
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] 0.555
Heat of formation [eV/atom] -0.122