| Structure info | |
|---|---|
| Layer group | pm2m |
| Layer group number | 27 |
| Structure origin | adhoc_material |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.000 |
| Heat of formation [eV/atom] | -1.898 |
| Dynamically stable | Yes |
| Basic properties | |
|---|---|
| Magnetic | No |
| Ferroelectric | Yes |
| Out-of-plane dipole [e Å/unit cell] | -0.000 |
| Band gap (PBE) [eV] | 1.041 |
| Band gap (HSE) [eV] | 1.951 |
| Symmetries | |
|---|---|
| 2D Bravais type | Rectangular (op) |
| Layer group number | 27 |
| Layer group | pm2m |
| Space group number (bulk in AA-stacking) | 25 |
| Space group (bulk in AA-stacking) | Pmm2 |
| Point group | mm2 |
| Inversion symmetry | No |
| Structure data | |
|---|---|
| Formula | Nb2Cl4O2 |
| Stoichiometry | ABC2 |
| Number of atoms | 8 |
| Unit cell area [Å2] | 26.564 |
| Thickness [Å] | 3.886 |
| Nb2O2Cl4 (2NbOCl2-1) | |
|---|---|
| Heat of formation [eV/atom] | -1.90 |
| Energy above convex hull [eV/atom] | 0.00 |
| Monolayers from C2DB | |
|---|---|
| Nb4O8 (4NbO2-1) | -2.42 eV/atom |
| Nb2O4 (2NbO2-1) | -2.38 eV/atom |
| NbO2 (1NbO2-1) | -2.37 eV/atom |
| NbO2 (1NbO2-2) | -2.35 eV/atom |
| Nb2Cl2O4 (2ClNbO2-1) | -2.32 eV/atom |
| NbO2 (1NbO2-3) | -2.20 eV/atom |
| Nb2Cl2O3 (1Cl2Nb2O3-1) | -2.09 eV/atom |
| Nb2O6 (2NbO3-1) | -2.07 eV/atom |
| Nb2Cl4O2, (2NbOCl2-1) | -1.90 eV/atom |
| Nb2Cl2O2 (2ClNbO-1) | -1.86 eV/atom |
| Nb4O12 (4NbO3-1) | -1.83 eV/atom |
| Nb2O2 (2NbO-1) | -1.53 eV/atom |
| Nb3Cl7O (1ONb3Cl7-1) | -1.49 eV/atom |
| Nb2Cl4O4 (2NbCl2O2-1) | -1.40 eV/atom |
| Nb3Cl8 (1Nb3Cl8-1) | -1.35 eV/atom |
| Nb2O2 (2NbO-2) | -1.30 eV/atom |
| Nb2Cl6 (2NbCl3-1) | -1.22 eV/atom |
| Nb2Cl6 (2NbCl3-2) | -1.19 eV/atom |
| NbCl4 (1NbCl4-1) | -1.16 eV/atom |
| Nb2Cl4 (2NbCl2-1) | -1.13 eV/atom |
| Nb2Cl2O (1OCl2Nb2-1) | -1.07 eV/atom |
| NbCl2 (1NbCl2-1) | -1.06 eV/atom |
| Nb2O2 (2NbO-3) | -1.02 eV/atom |
| NbCl2 (1NbCl2-2) | -0.96 eV/atom |
| NbCl2 (1NbCl2-3) | -0.76 eV/atom |
| Nb2Cl2 (2ClNb-1) | -0.17 eV/atom |
| Nb2Cl2 (2ClNb-2) | -0.10 eV/atom |
| Minimum eigenvalue of Hessian [eV/Ų] | -0.00 |
| DVB [eV] | xx | yy | xy |
| Γ | 1.78 | 4.22 | 0.00 |
| X | 1.41 | 4.04 | 0.00 |
| S | 1.75 | -2.28 | 0.00 |
| Y | 2.48 | -2.43 | 0.00 |
| kVBM | 1.75 | -2.28 | 0.00 |
| xx | yy | xy | |
| Band gap [eV] | 8.06 | 1.56 | 0.01 |
| DCB [eV] | xx | yy | xy |
| Γ | 11.24 | -1.66 | 0.01 |
| X | 0.36 | -8.48 | 0.00 |
| S | 0.47 | 1.80 | 0.01 |
| Y | 9.81 | -0.72 | 0.01 |
| kCBM | 9.81 | -0.72 | 0.01 |
| Cij (N/m) | xx | yy | xy |
| xx | 85.25 | 5.53 | -0.09 |
| yy | 4.80 | 66.05 | -0.04 |
| xy | 0.00 | 0.01 | 30.47 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 30.47 N/m |
| Eigenvalue 1 | 64.76 N/m |
| Eigenvalue 2 | 86.55 N/m |
| cij [e/Å] | xx | yy | xy |
| x | 1.26 | -0.02 | 0.00 |
| y | 0.00 | -0.00 | 0.04 |
| z | -0.00 | -0.00 | -0.00 |
| cijclamped [e/Å] | xx | yy | xy |
| x | -0.00 | 0.01 | -0.00 |
| y | 0.00 | 0.00 | 0.03 |
| z | -0.00 | 0.00 | 0.00 |
| Properties [eV] | |
|---|---|
| Band gap | 1.041 |
| Direct band gap | 1.119 |
| VBM wrt. vacuum | -5.964 |
| CBM wrt. vacuum | -4.923 |
| Vacuum level shift | -0.000 |
| Properties [eV] | |
|---|---|
| Band gap | 1.951 |
| Direct band gap | 2.030 |
| VBM wrt. vacuum | -6.263 |
| CBM wrt. vacuum | -4.312 |
| Property (VBM) | Value |
|---|---|
| Min eff. mass | 11.67 m0 |
| Max eff. mass | 25.41 m0 |
| DOS eff. mass | 15.81 m0 |
| Crystal coordinates | [0.500, 0.482] |
| Warping parameter | -0.004 |
| Barrier height | 0.0 meV |
| Distance to barrier | 0.00201 Å-1 |
| Property (CBM) | Value |
|---|---|
| Min eff. mass | 0.19 m0 |
| Max eff. mass | 0.59 m0 |
| DOS eff. mass | 0.32 m0 |
| Crystal coordinates | [-0.000, 0.496] |
| Warping parameter | 0.003 |
| Barrier height | > 18.8 meV |
| Distance to barrier | > 0.0159 Å-1 |
| ZNbij | ux | uy | uz |
| Px | 6.51 | -0.01 | 0.00 |
| Py | -0.38 | 3.78 | 0.00 |
| Pz | 0.00 | 0.00 | 0.71 |
| ZClij | ux | uy | uz |
| Px | -0.35 | 0.00 | -0.13 |
| Py | -0.00 | -0.51 | -0.00 |
| Pz | -0.03 | -0.00 | -0.28 |
| ZClij | ux | uy | uz |
| Px | -0.44 | 0.00 | 0.04 |
| Py | -0.00 | -2.14 | 0.00 |
| Pz | 0.02 | -0.00 | -0.23 |
| ZOij | ux | uy | uz |
| Px | -5.72 | 0.11 | -0.00 |
| Py | 0.44 | -1.13 | 0.00 |
| Pz | -0.00 | -0.00 | -0.20 |
| ZClij | ux | uy | uz |
| Px | -0.44 | -0.00 | -0.04 |
| Py | 0.00 | -2.14 | 0.00 |
| Pz | -0.02 | -0.00 | -0.23 |
| ZNbij | ux | uy | uz |
| Px | 6.51 | 0.01 | -0.00 |
| Py | 0.38 | 3.78 | 0.00 |
| Pz | -0.00 | 0.00 | 0.71 |
| ZClij | ux | uy | uz |
| Px | -0.35 | -0.00 | 0.13 |
| Py | 0.00 | -0.51 | -0.00 |
| Pz | 0.03 | -0.00 | -0.28 |
| ZOij | ux | uy | uz |
| Px | -5.72 | -0.11 | 0.00 |
| Py | -0.44 | -1.13 | 0.00 |
| Pz | 0.00 | -0.00 | -0.20 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | Nb | 2.13 |
| 1 | Cl | -0.57 |
| 2 | Cl | -0.53 |
| 3 | Nb | 2.13 |
| 4 | Cl | -0.57 |
| 5 | Cl | -0.53 |
| 6 | O | -1.02 |
| 7 | O | -1.02 |
| Spontaneous polarization vector component [pC/m] | |
|---|---|
| Px | 213.459 |
| Py | -0.004 |
| Pz | -0.000 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 1.556 |
| Interband polarizability (y) [Å] | 2.329 |
| Interband polarizability (z) [Å] | 0.339 |
| Static polarizability [Å] | |
|---|---|
| Phonons only (x) | 2.67 |
| Phonons only (y) | 2.56 |
| Phonons only (z) | 0.03 |
| Total (phonons + electrons) (x) | 4.22 |
| Total (phonons + electrons) (y) | 4.89 |
| Total (phonons + electrons) (z) | 0.37 |
| Element | Relations |
|---|---|
| xxx | |
| xyx | xyx=xxy |
| xyy | |
| xzz | |
| yxx | |
| yxy | yxy=yyx |
| yyy | |
| yzz | |
| Others | 0=xxz=xyz=xzx=xzy=yxz=yyz=yzx=yzy=zxx=zxy=zyx=zyy= zzz |
| zxz | zxz=zzx |
| zyz | zyz=zzy |
| Miscellaneous details | |
|---|---|
| Unique ID | 2NbOCl2-1 |
| Number of atoms | 8 |
| Number of species | 3 |
| Formula | Nb2Cl4O2 |
| Reduced formula | NbCl2O |
| Stoichiometry | ABC2 |
| Unit cell area [Å2] | 26.564 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/adhoc_materials/Nb2O2Cl4 |
| Old uid | Nb2O2Cl4-29323693cd83 |
| Space group (bulk in AA-stacking) | Pmm2 |
| Space group number (bulk in AA-stacking) | 25 |
| Point group | mm2 |
| Inversion symmetry | No |
| Layer group number | 27 |
| Layer group | pm2m |
| 2D Bravais type | Rectangular (op) |
| Thickness [Å] | 3.886 |
| Structure origin | adhoc_material |
| Band gap [eV] | 1.041 |
| Direct band gap [eV] | 1.119 |
| gap_dir_nosoc | 1.120 |
| Vacuum level [eV] | 1.772 |
| Fermi level wrt. vacuum [eV] | -5.443 |
| VBM wrt. vacuum [eV] | -5.964 |
| CBM wrt. vacuum [eV] | -4.923 |
| Vacuum level shift [eV] | -0.000 |
| Out-of-plane dipole [e Å/unit cell] | -0.000 |
| Miscellaneous details | |
|---|---|
| minhessianeig | -0.000 |
| Dynamically stable | Yes |
| Band gap [eV] | 1.951 |
| Direct band gap [eV] | 2.030 |
| Fermi level wrt. vacuum [eV] | -5.287 |
| VBM wrt. vacuum [eV] | -6.263 |
| CBM wrt. vacuum [eV] | -4.312 |
| Interband polarizability (x) [Å] | 1.556 |
| Interband polarizability (y) [Å] | 2.329 |
| Interband polarizability (z) [Å] | 0.339 |
| Static polarizability (phonons) (x) [Å] | 2.669 |
| Static polarizability (phonons + electrons) (x) [Å] | 4.225 |
| Static polarizability (phonons) (y) [Å] | 2.564 |
| Static polarizability (phonons + electrons) (y) [Å] | 4.893 |
| Static polarizability (phonons) (z) [Å] | 0.028 |
| Static polarizability (phonons + electrons) (z) [Å] | 0.366 |
| Energy [eV] | -53.226 |
| Magnetic | No |
| Total magnetic moment [μB] | 0.000 |
| Spin axis | z |
| Magnetic anisotropy energy, xz [meV/unit cell] | 0.000 |
| Magnetic anisotropy energy, yz [meV/unit cell] | 0.000 |
| Ferroelectric | Yes |
| Spontaneous polarization [pC/m] | 213.459 |
| Energy above convex hull [eV/atom] | 0.000 |
| Heat of formation [eV/atom] | -1.898 |
