| Structure info | |
|---|---|
| Layer group | p4/mmm |
| Layer group number | 61 |
| Structure origin | original03-18 |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.345 |
| Heat of formation [eV/atom] | -0.460 |
| Dynamically stable | No |
| Basic properties | |
|---|---|
| Magnetic | No |
| Band gap (PBE) [eV] | 0.000 |
| Symmetries | |
|---|---|
| 2D Bravais type | Square (tp) |
| Layer group number | 61 |
| Layer group | p4/mmm |
| Space group number (bulk in AA-stacking) | 123 |
| Space group (bulk in AA-stacking) | P4/mmm |
| Point group | 4/mmm |
| Inversion symmetry | Yes |
| Structure data | |
|---|---|
| Formula | Nb2Se2 |
| Stoichiometry | AB |
| Number of atoms | 4 |
| Unit cell area [Å2] | 15.181 |
| Thickness [Å] | 3.709 |
| Nb2Se2 (2NbSe-3) | |
|---|---|
| Heat of formation [eV/atom] | -0.46 |
| Energy above convex hull [eV/atom] | 0.34 |
| Monolayers from C2DB | |
|---|---|
| Nb7Se12 (1Nb7Se12-1) | -0.90 eV/atom |
| Nb8Se12 (4Nb2Se3-1) | -0.88 eV/atom |
| NbSe2 (1NbSe2-1) | -0.88 eV/atom |
| Nb4Se6 (2Nb2Se3-1) | -0.87 eV/atom |
| Nb7Se12 (1Nb7Se12-2) | -0.85 eV/atom |
| NbSe2 (1NbSe2-2) | -0.85 eV/atom |
| Nb9Se12 (3Nb3Se4-1) | -0.82 eV/atom |
| Nb8Se12 (4Nb2Se3-2) | -0.80 eV/atom |
| Nb9Se12 (3Nb3Se4-2) | -0.75 eV/atom |
| Nb4Se12 (4NbSe3-1) | -0.70 eV/atom |
| Nb2Se6 (2NbSe3-1) | -0.67 eV/atom |
| Se2Nb4 (2SeNb2-1) | -0.55 eV/atom |
| Nb2Se2 (2NbSe-1) | -0.53 eV/atom |
| Nb2Se2 (2NbSe-2) | -0.51 eV/atom |
| Nb2Se2, (2NbSe-3) | -0.46 eV/atom |
| NbSe2 (1NbSe2-3) | -0.44 eV/atom |
| Nb2Se2 (2NbSe-4) | -0.25 eV/atom |
| Nb2Se2 (2NbSe-5) | -0.23 eV/atom |
| Se2 (2Se-1) | 0.21 eV/atom |
| Se2 (2Se-2) | 0.29 eV/atom |
| Minimum eigenvalue of Hessian [eV/Ų] | -2.41 |
| Cij (N/m) | xx | yy | xy |
| xx | 67.15 | 47.94 | -0.00 |
| yy | 47.69 | 67.52 | -0.00 |
| xy | 0.00 | 0.00 | 98.23 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 19.52 N/m |
| Eigenvalue 1 | 98.23 N/m |
| Eigenvalue 2 | 115.14 N/m |
| Key values [eV] | |
|---|---|
| Band gap (PBE) | 0.000 |
| Direct band gap (PBE) | 0.000 |
| Fermi level wrt. vacuum (PBE) | -4.882 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | Nb | 0.79 |
| 1 | Se | -0.79 |
| 2 | Nb | 0.79 |
| 3 | Se | -0.79 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 19.295 |
| Interband polarizability (y) [Å] | 18.319 |
| Interband polarizability (z) [Å] | 0.477 |
| Plasma frequency (x) [eV Å0.5] | 10.908 |
| Plasma frequency (y) [eV Å0.5] | 10.942 |
| Miscellaneous details | |
|---|---|
| Unique ID | 2NbSe-3 |
| Number of atoms | 4 |
| Number of species | 2 |
| Formula | Nb2Se2 |
| Reduced formula | NbSe |
| Stoichiometry | AB |
| Unit cell area [Å2] | 15.181 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/tree/AB/NbSe/Nb2Se2-c9e9c08ae72e |
| Old uid | Nb2Se2-c9e9c08ae72e |
| Space group (bulk in AA-stacking) | P4/mmm |
| Space group number (bulk in AA-stacking) | 123 |
| Point group | 4/mmm |
| Inversion symmetry | Yes |
| Layer group number | 61 |
| Layer group | p4/mmm |
| 2D Bravais type | Square (tp) |
| Thickness [Å] | 3.709 |
| 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] | 4.162 |
| Fermi level wrt. vacuum (PBE) [eV] | -4.882 |
| minhessianeig | -2.405 |
| Dynamically stable | No |
| Interband polarizability (x) [Å] | 19.295 |
| Interband polarizability (y) [Å] | 18.319 |
| Interband polarizability (z) [Å] | 0.477 |
| Plasma frequency (x) [eV Å0.5] | 10.908 |
| Plasma frequency (y) [eV Å0.5] | 10.942 |
| Energy [eV] | -29.458 |
| 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] | 0.345 |
| Heat of formation [eV/atom] | -0.460 |
