Structure info
Layer group p4/nmm
Layer group number 64
Structure origin original03-18
Stability
Energy above convex hull [eV/atom] 0.298
Heat of formation [eV/atom] -0.379
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 3.866 -0.000 0.000 Yes
2 -0.000 3.866 0.000 Yes
3 0.000 0.000 18.349 No
Lengths [Å] 3.866 3.866 18.349
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 Ta2Se2
Stoichiometry AB
Number of atoms 4
Unit cell area [Å2] 14.943
Thickness [Å] 3.742

Se2Ta2 (2SeTa-1)
Heat of formation [eV/atom] -0.38
Energy above convex hull [eV/atom] 0.30
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/1/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -14.25

Cij (N/m) xx yy xy
xx 17.14 127.55 -0.00
yy 127.73 17.15 -0.00
xy 0.00 0.00 -5.48
Stiffness tensor eigenvalues
Eigenvalue 0 -110.49 N/m
Eigenvalue 1 -5.48 N/m
Eigenvalue 2 144.79 N/m

Key values [eV]
Band gap (PBE) 0.000
Direct band gap (PBE) 0.000
Fermi level wrt. vacuum (PBE) -5.385
DOS BZ

AB/2SeTa/1/fermi_surface.png

Atom No. Chemical symbol Charges [|e|]
0 Ta 0.78
1 Ta 0.78
2 Se -0.78
3 Se -0.78

AB/2SeTa/1/rpa-pol-x.png AB/2SeTa/1/rpa-pol-z.png
AB/2SeTa/1/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 105.758
Interband polarizability (y) [Å] 101.449
Interband polarizability (z) [Å] 0.467
Plasma frequency (x) [eV Å0.5] 7.782
Plasma frequency (y) [eV Å0.5] 7.855

Miscellaneous details
Unique ID 2SeTa-1
Number of atoms 4
Number of species 2
Formula Ta2Se2
Reduced formula TaSe
Stoichiometry AB
Unit cell area [Å2] 14.943
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/AB/SeTa/Se2Ta2-cfa7477c5e85
Old uid Se2Ta2-cfa7477c5e85
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] 3.742
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] 4.167
Fermi level wrt. vacuum (PBE) [eV] -5.385
minhessianeig -14.251
Dynamically stable No
Interband polarizability (x) [Å] 105.758
Interband polarizability (y) [Å] 101.449
Interband polarizability (z) [Å] 0.467
Plasma frequency (x) [eV Å0.5] 7.782
Plasma frequency (y) [eV Å0.5] 7.855
Energy [eV] -28.113
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] 0.298
Heat of formation [eV/atom] -0.379