| Structure info | |
|---|---|
| Layer group | p4/nmm |
| Layer group number | 64 |
| Structure origin | exfoliated02-21 |
| COD id of parent bulk structure | COD 1540056 |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.000 |
| Heat of formation [eV/atom] | -0.487 |
| Dynamically stable | Yes |
| Basic properties | |
|---|---|
| Magnetic | No |
| Band gap (PBE) [eV] | 0.000 |
| 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 | Ta4Se2 |
| Stoichiometry | AB2 |
| Number of atoms | 6 |
| Unit cell area [Å2] | 11.507 |
| Thickness [Å] | 7.275 |
| Se2Ta4 (2SeTa2-1) | |
|---|---|
| Heat of formation [eV/atom] | -0.49 |
| Energy above convex hull [eV/atom] | 0.00 |
| 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 |
| Minimum eigenvalue of Hessian [eV/Ų] | -0.00 |
| Cij (N/m) | xx | yy | xy |
| xx | 210.76 | 95.57 | -0.00 |
| yy | 95.57 | 210.76 | -0.00 |
| xy | 0.00 | 0.00 | 188.30 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 115.19 N/m |
| Eigenvalue 1 | 188.30 N/m |
| Eigenvalue 2 | 306.32 N/m |
| Key values [eV] | |
|---|---|
| Band gap (PBE) | 0.000 |
| Direct band gap (PBE) | 0.000 |
| Fermi level wrt. vacuum (PBE) | -3.720 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | Ta | 0.63 |
| 1 | Se | -0.89 |
| 2 | Ta | 0.26 |
| 3 | Ta | 0.63 |
| 4 | Se | -0.89 |
| 5 | Ta | 0.26 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 114.598 |
| Interband polarizability (y) [Å] | 114.598 |
| Interband polarizability (z) [Å] | 1.066 |
| Plasma frequency (x) [eV Å0.5] | 6.820 |
| Plasma frequency (y) [eV Å0.5] | 6.820 |
| Miscellaneous details | |
|---|---|
| Unique ID | 2SeTa2-1 |
| Number of atoms | 6 |
| Number of species | 2 |
| Formula | Ta4Se2 |
| Reduced formula | Ta2Se |
| Stoichiometry | AB2 |
| Unit cell area [Å2] | 11.507 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/ICSD-COD/2el/Ta4Se2 |
| Old uid | Se2Ta4-683e13afb9a4 |
| 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] | 7.275 |
| 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] | 3.947 |
| Fermi level wrt. vacuum (PBE) [eV] | -3.720 |
| minhessianeig | -0.000 |
| Dynamically stable | Yes |
| Interband polarizability (x) [Å] | 114.598 |
| Interband polarizability (y) [Å] | 114.598 |
| Interband polarizability (z) [Å] | 1.066 |
| Plasma frequency (x) [eV Å0.5] | 6.820 |
| Plasma frequency (y) [eV Å0.5] | 6.820 |
| Energy [eV] | -49.153 |
| COD id of parent bulk structure | COD 1540056 |
| 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] | 0.000 |
| Heat of formation [eV/atom] | -0.487 |
