| Structure info | |
|---|---|
| Layer group | p-6m2 |
| Layer group number | 78 |
| Structure origin | original03-18 |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.126 |
| Heat of formation [eV/atom] | -1.005 |
| Dynamically stable | Yes |
| Basic properties | |
|---|---|
| Magnetic | No |
| Band gap (PBE) [eV] | 0.522 |
| Band gap (HSE06) [eV] | 1.460 |
| Band gap (G₀W₀) [eV] | 1.481 |
| 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 | TiSe2 |
| Stoichiometry | AB2 |
| Number of atoms | 3 |
| Unit cell area [Å2] | 10.580 |
| Thickness [Å] | 3.240 |
| TiSe2 (1TiSe2-2) | |
|---|---|
| Heat of formation [eV/atom] | -1.00 |
| Energy above convex hull [eV/atom] | 0.13 |
| Monolayers from C2DB | |
|---|---|
| Ti4Se8 (4TiSe2-1) | -1.13 eV/atom |
| Ti2Se3 (1Ti2Se3-1) | -1.12 eV/atom |
| TiSe2 (1TiSe2-1) | -1.12 eV/atom |
| TiSe2, (1TiSe2-2) | -1.00 eV/atom |
| Ti2Se2 (2SeTi-1) | -0.87 eV/atom |
| TiSe2 (1TiSe2-3) | -0.86 eV/atom |
| Ti2Se2 (2SeTi-2) | -0.83 eV/atom |
| Ti2Se6 (2TiSe3-1) | -0.83 eV/atom |
| Ti2Se2 (2SeTi-3) | -0.78 eV/atom |
| Ti2Se2 (2SeTi-4) | -0.56 eV/atom |
| Ti2Se2 (2SeTi-5) | -0.55 eV/atom |
| Se2 (2Se-1) | 0.21 eV/atom |
| Se2 (2Se-2) | 0.29 eV/atom |
| Minimum eigenvalue of Hessian [eV/Ų] | -0.00 |
| DVB [eV] | xx | yy | xy |
| Γ | -4.94 | -4.95 | -0.00 |
| M | -1.59 | -5.31 | 3.28 |
| K | 1.18 | 1.20 | -0.00 |
| kVBM | -4.94 | -4.95 | -0.00 |
| xx | yy | xy | |
| Band gap [eV] | 3.54 | 5.02 | -1.36 |
| DCB [eV] | xx | yy | xy |
| Γ | -0.29 | -0.27 | -0.00 |
| M | -1.50 | 0.25 | -1.60 |
| K | -3.56 | -3.58 | -0.00 |
| kCBM | -1.41 | 0.07 | -1.36 |
| Cij (N/m) | xx | yy | xy |
| xx | 75.02 | 23.66 | -0.00 |
| yy | 23.78 | 74.65 | -0.00 |
| xy | 0.00 | 0.00 | 50.43 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 50.43 N/m |
| Eigenvalue 1 | 51.11 N/m |
| Eigenvalue 2 | 98.55 N/m |
| cij [e/Å] | xx | yy | xy |
| x | -0.00 | -0.00 | -0.14 |
| y | -0.17 | 0.17 | 0.00 |
| z | -0.00 | 0.00 | 0.00 |
| cijclamped [e/Å] | xx | yy | xy |
| x | -0.00 | -0.00 | -0.35 |
| y | -0.35 | 0.35 | -0.00 |
| z | 0.00 | -0.00 | 0.00 |
| Key values [eV] | |
|---|---|
| Band gap (PBE) | 0.522 |
| Direct band gap (PBE) | 0.867 |
| Valence band maximum wrt. vacuum (PBE) | -6.093 |
| Conduction band minimum wrt. vacuum (PBE) | -5.571 |
| Key values [eV] | |
|---|---|
| Band gap (HSE06) | 1.460 |
| Direct band gap (HSE06) | 2.046 |
| Valence band maximum wrt. vacuum (HSE06) | -6.286 |
| Conduction band minimum wrt. vacuum (HSE06) | -4.826 |
| Key values [eV] | |
|---|---|
| Band gap (G₀W₀) | 1.481 |
| Direct band gap (G₀W₀) | 2.174 |
| Valence band maximum wrt. vacuum (G₀W₀) | -6.416 |
| Conduction band minimum wrt. vacuum (G₀W₀) | -4.936 |
| Property (VBM) | Value |
|---|---|
| Min eff. mass | 1.49 m0 |
| Max eff. mass | 1.56 m0 |
| DOS eff. mass | 1.53 m0 |
| Crystal coordinates | [0.000, 0.000] |
| Warping parameter | -0.020 |
| Barrier height | > 15.0 meV |
| Distance to barrier | > 0.0207 Å-1 |
| Property (CBM) | Value |
|---|---|
| Min eff. mass | 0.45 m0 |
| Max eff. mass | 2.13 m0 |
| DOS eff. mass | 0.97 m0 |
| Crystal coordinates | [0.402, 0.006] |
| Warping parameter | 0.005 |
| Barrier height | > 16.8 meV |
| Distance to barrier | > 0.0209 Å-1 |
| ZTiij | ux | uy | uz |
| Px | 4.38 | -0.00 | 0.00 |
| Py | -0.00 | 4.38 | 0.00 |
| Pz | -0.00 | -0.00 | 0.35 |
| ZSeij | ux | uy | uz |
| Px | -2.19 | 0.00 | 0.00 |
| Py | 0.00 | -2.19 | -0.00 |
| Pz | -0.00 | -0.00 | -0.18 |
| ZSeij | ux | uy | uz |
| Px | -2.19 | 0.00 | -0.00 |
| Py | 0.00 | -2.19 | 0.00 |
| Pz | 0.00 | -0.00 | -0.18 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | Ti | 1.55 |
| 1 | Se | -0.77 |
| 2 | Se | -0.78 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 7.311 |
| Interband polarizability (y) [Å] | 7.311 |
| Interband polarizability (z) [Å] | 0.404 |
| Plasma frequency (x) [eV Å0.5] | 0.000 |
| Plasma frequency (y) [eV Å0.5] | 0.000 |
| Static polarizability [Å] | |
|---|---|
| Phonons only (x) | 3.81 |
| Phonons only (y) | 3.81 |
| Phonons only (z) | 0.01 |
| Total (phonons + electrons) (x) | 11.12 |
| Total (phonons + electrons) (y) | 11.12 |
| Total (phonons + electrons) (z) | 0.42 |
| Exciton binding energy (BSE) [eV] | 0.72 |
| Element | Relations |
|---|---|
| yyy | yyy=-xxy=-yxx=-xyx |
| Others | 0=xxx=xxz=xyy=xyz=xzx=xzy=xzz=yxy=yxz=yyx=yyz=yzx= yzy=yzz=zxx=zxy=zxz=zyx=zyy=zyz=zzx=zzy=zzz |
| Element | Relations |
|---|---|
| yyy | yyy=-xyx=-yxx=-xxy |
| Others | 0=xxx=xxz=xyy=xyz=xzx=xzy=xzz=yxy=yxz=yyx=yyz=yzx= yzy=yzz=zxx=zxy=zxz=zyx=zyy=zyz=zzx=zzy=zzz |
| Mode | Frequency (1/cm) | Degeneracy |
|---|---|---|
| Mode 1 | 0. | 3 |
| Mode 2 | 61. | 2 |
| Mode 3 | 216.4 | 1 |
| Mode 4 | 227.3 | 2 |
| Mode 5 | 298.1 | 1 |
| Miscellaneous details | |
|---|---|
| Unique ID | 1TiSe2-2 |
| Number of atoms | 3 |
| Number of species | 2 |
| Formula | TiSe2 |
| Reduced formula | TiSe2 |
| Stoichiometry | AB2 |
| Unit cell area [Å2] | 10.580 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/tree/AB2/TiSe2/TiSe2-509ef368050d |
| Old uid | TiSe2-509ef368050d |
| 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] | 3.240 |
| Structure origin | original03-18 |
| Band gap (PBE) [eV] | 0.522 |
| Direct band gap (PBE) [eV] | 0.867 |
| gap_dir_nosoc | 0.943 |
| Vacuum level [eV] | 3.980 |
| Fermi level wrt. vacuum (PBE) [eV] | -5.832 |
| Valence band maximum wrt. vacuum (PBE) [eV] | -6.093 |
| Conduction band minimum wrt. vacuum (PBE) [eV] | -5.571 |
| minhessianeig | -0.000 |
| Dynamically stable | Yes |
| Band gap (HSE06) [eV] | 1.460 |
| Miscellaneous details | |
|---|---|
| Direct band gap (HSE06) [eV] | 2.046 |
| Fermi level wrt. vacuum (HSE) [eV] | -5.600 |
| Valence band maximum wrt. vacuum (HSE06) [eV] | -6.286 |
| Conduction band minimum wrt. vacuum (HSE06) [eV] | -4.826 |
| Band gap (G₀W₀) [eV] | 1.481 |
| Direct band gap (G₀W₀) [eV] | 2.174 |
| Fermi level wrt. vacuum (G₀W₀) [eV] | -5.676 |
| Valence band maximum wrt. vacuum (G₀W₀) [eV] | -6.416 |
| Conduction band minimum wrt. vacuum (G₀W₀) [eV] | -4.936 |
| E_B | 0.716 |
| Interband polarizability (x) [Å] | 7.311 |
| Interband polarizability (y) [Å] | 7.311 |
| Interband polarizability (z) [Å] | 0.404 |
| Static polarizability (phonons) (x) [Å] | 3.809 |
| Static polarizability (phonons + electrons) (x) [Å] | 11.120 |
| Static polarizability (phonons) (y) [Å] | 3.808 |
| Static polarizability (phonons + electrons) (y) [Å] | 11.119 |
| Static polarizability (phonons) (z) [Å] | 0.014 |
| Static polarizability (phonons + electrons) (z) [Å] | 0.418 |
| Plasma frequency (x) [eV Å0.5] | 0.000 |
| Plasma frequency (y) [eV Å0.5] | 0.000 |
| Energy [eV] | -16.670 |
| 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] | 0.126 |
| Heat of formation [eV/atom] | -1.005 |
