| Structure info | |
|---|---|
| Layer group | p4/mbm |
| Layer group number | 63 |
| Structure origin | original03-18 |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.331 |
| Heat of formation [eV/atom] | 0.269 |
| Dynamically stable | No |
| Basic properties | |
|---|---|
| Magnetic | No |
| Topology | Z2=1,C_M=1 |
| Band gap (PBE) [eV] | 0.032 |
| Band gap (HSE06) [eV] | 0.134 |
| Symmetries | |
|---|---|
| 2D Bravais type | Square (tp) |
| Layer group number | 63 |
| Layer group | p4/mbm |
| Space group number (bulk in AA-stacking) | 127 |
| Space group (bulk in AA-stacking) | P4/mbm |
| Point group | 4/mmm |
| Inversion symmetry | Yes |
| Structure data | |
|---|---|
| Formula | Te4Ge2 |
| Stoichiometry | AB2 |
| Number of atoms | 6 |
| Unit cell area [Å2] | 53.822 |
| Thickness [Å] | 0.003 |
| Ge2Te4 (2GeTe2-2) | |
|---|---|
| Heat of formation [eV/atom] | 0.27 |
| Energy above convex hull [eV/atom] | 0.33 |
| Monolayers from C2DB | |
|---|---|
| Te2Ge2 (2GeTe-1) | -0.04 eV/atom |
| TeGe (1GeTe-1) | -0.01 eV/atom |
| Te2Ge2 (2GeTe-2) | -0.00 eV/atom |
| Te2Ge (1GeTe2-1) | 0.07 eV/atom |
| Te2Ge (1GeTe2-2) | 0.08 eV/atom |
| Te4Ge2 (2GeTe2-1) | 0.14 eV/atom |
| Te2 (2Te-1) | 0.16 eV/atom |
| Te2Ge (1GeTe2-3) | 0.20 eV/atom |
| Te4Ge2, (2GeTe2-2) | 0.27 eV/atom |
| Te2 (2Te-2) | 0.29 eV/atom |
| Te2Ge2 (2GeTe-3) | 0.38 eV/atom |
| Ge2 (2Ge-1) | 0.48 eV/atom |
| Ge2 (2Ge-2) | 0.49 eV/atom |
| Minimum eigenvalue of Hessian [eV/Ų] | -0.83 |
| Cij (N/m) | xx | yy | xy |
| xx | 30.36 | 18.91 | -0.00 |
| yy | 18.91 | 30.82 | 0.00 |
| xy | -0.00 | 0.00 | 2.07 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 2.07 N/m |
| Eigenvalue 1 | 11.68 N/m |
| Eigenvalue 2 | 49.50 N/m |
| Key values [eV] | |
|---|---|
| Band gap (PBE) | 0.032 |
| Direct band gap (PBE) | 0.174 |
| Valence band maximum wrt. vacuum (PBE) | -4.490 |
| Conduction band minimum wrt. vacuum (PBE) | -4.457 |
| Key values [eV] | |
|---|---|
| Band gap (HSE06) | 0.134 |
| Direct band gap (HSE06) | 0.214 |
| Valence band maximum wrt. vacuum (HSE06) | -4.473 |
| Conduction band minimum wrt. vacuum (HSE06) | -4.339 |
| Property (VBM) | Value |
|---|---|
| Min eff. mass | 0.05 m0 |
| Max eff. mass | 0.06 m0 |
| DOS eff. mass | 0.06 m0 |
| Crystal coordinates | [0.139, 0.139] |
| Warping parameter | -0.016 |
| Barrier height | > 132.0 meV |
| Distance to barrier | > 0.0116 Å-1 |
| Property (CBM) | Value |
|---|---|
| Min eff. mass | 0.06 m0 |
| Max eff. mass | 0.11 m0 |
| DOS eff. mass | 0.08 m0 |
| Crystal coordinates | [-0.000, 0.116] |
| Warping parameter | 0.028 |
| Barrier height | > 86.0 meV |
| Distance to barrier | > 0.0114 Å-1 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | Ge | 0.38 |
| 1 | Ge | 0.38 |
| 2 | Te | -0.18 |
| 3 | Te | -0.18 |
| 4 | Te | -0.20 |
| 5 | Te | -0.20 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 11.379 |
| Interband polarizability (y) [Å] | 11.590 |
| Interband polarizability (z) [Å] | 0.252 |
| Plasma frequency (x) [eV Å0.5] | 4.287 |
| Plasma frequency (y) [eV Å0.5] | 4.489 |
| Miscellaneous details | |
|---|---|
| Unique ID | 2GeTe2-2 |
| Number of atoms | 6 |
| Number of species | 2 |
| Formula | Te4Ge2 |
| Reduced formula | Te2Ge |
| Stoichiometry | AB2 |
| Unit cell area [Å2] | 53.822 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/tree/AB2/GeTe2/Ge2Te4-be93b1621bc7 |
| Old uid | Ge2Te4-be93b1621bc7 |
| Space group (bulk in AA-stacking) | P4/mbm |
| Space group number (bulk in AA-stacking) | 127 |
| Point group | 4/mmm |
| Inversion symmetry | Yes |
| Layer group number | 63 |
| Layer group | p4/mbm |
| 2D Bravais type | Square (tp) |
| Thickness [Å] | 0.003 |
| Structure origin | original03-18 |
| Band gap (PBE) [eV] | 0.032 |
| Direct band gap (PBE) [eV] | 0.174 |
| gap_dir_nosoc | 0.178 |
| Vacuum level [eV] | 2.134 |
| Fermi level wrt. vacuum (PBE) [eV] | -4.473 |
| Miscellaneous details | |
|---|---|
| Valence band maximum wrt. vacuum (PBE) [eV] | -4.490 |
| Conduction band minimum wrt. vacuum (PBE) [eV] | -4.457 |
| minhessianeig | -0.826 |
| Dynamically stable | No |
| Band gap (HSE06) [eV] | 0.134 |
| Direct band gap (HSE06) [eV] | 0.214 |
| Fermi level wrt. vacuum (HSE) [eV] | -4.406 |
| Valence band maximum wrt. vacuum (HSE06) [eV] | -4.473 |
| Conduction band minimum wrt. vacuum (HSE06) [eV] | -4.339 |
| Interband polarizability (x) [Å] | 11.379 |
| Interband polarizability (y) [Å] | 11.590 |
| Interband polarizability (z) [Å] | 0.252 |
| Plasma frequency (x) [eV Å0.5] | 4.287 |
| Plasma frequency (y) [eV Å0.5] | 4.489 |
| Energy [eV] | -20.236 |
| Magnetic | No |
| Spin axis | z |
| Magnetic anisotropy energy, xz [meV/unit cell] | 0.000 |
| Magnetic anisotropy energy, yz [meV/unit cell] | 0.000 |
| Topology | Z2=1,C_M=1 |
| Energy above convex hull [eV/atom] | 0.331 |
| Heat of formation [eV/atom] | 0.269 |
