| Structure info | |
|---|---|
| Layer group | p2/m11 |
| Layer group number | 14 |
| Structure origin | original03-18 |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.089 |
| Heat of formation [eV/atom] | 0.022 |
| Dynamically stable | Yes |
| Basic properties | |
|---|---|
| Magnetic | No |
| Band gap (PBE) [eV] | 0.750 |
| Band gap (HSE06) [eV] | 1.179 |
| Symmetries | |
|---|---|
| 2D Bravais type | Rectangular (op) |
| Layer group number | 14 |
| Layer group | p2/m11 |
| Space group number (bulk in AA-stacking) | 10 |
| Space group (bulk in AA-stacking) | P2/m |
| Point group | 2/m |
| Inversion symmetry | Yes |
| Structure data | |
|---|---|
| Formula | Ag2Se2 |
| Stoichiometry | AB |
| Number of atoms | 4 |
| Unit cell area [Å2] | 22.760 |
| Thickness [Å] | 2.760 |
| Ag2Se2 (2AgSe-1) | |
|---|---|
| Heat of formation [eV/atom] | 0.02 |
| Energy above convex hull [eV/atom] | 0.09 |
| Monolayers from C2DB | |
|---|---|
| Se2Ag4 (2SeAg2-1) | -0.09 eV/atom |
| Se8Ag16 (8SeAg2-1) | -0.07 eV/atom |
| Ag4Se4 (4AgSe-1) | -0.02 eV/atom |
| Ag2Se2, (2AgSe-1) | 0.02 eV/atom |
| Ag8Se12 (4Ag2Se3-1) | 0.03 eV/atom |
| Ag2Se4 (2AgSe2-1) | 0.05 eV/atom |
| Ag2Se2 (2AgSe-2) | 0.05 eV/atom |
| Ag2Se2 (2AgSe-3) | 0.06 eV/atom |
| AgSe2 (1AgSe2-1) | 0.11 eV/atom |
| SeAg2 (1SeAg2-1) | 0.15 eV/atom |
| Ag2Se2 (2AgSe-4) | 0.15 eV/atom |
| Ag2Se2 (2AgSe-5) | 0.18 eV/atom |
| Ag2Se4 (2AgSe2-2) | 0.19 eV/atom |
| Se2 (2Se-1) | 0.21 eV/atom |
| AgSe2 (1AgSe2-2) | 0.22 eV/atom |
| Ag2Se2 (2AgSe-6) | 0.27 eV/atom |
| Se2 (2Se-2) | 0.29 eV/atom |
| Ag2 (2Ag-1) | 0.31 eV/atom |
| AgSe2 (1AgSe2-3) | 0.32 eV/atom |
| Minimum eigenvalue of Hessian [eV/Ų] | -0.00 |
| DVB [eV] | xx | yy | xy |
| Γ | -0.94 | -0.03 | -0.00 |
| X | -2.03 | -0.69 | 0.00 |
| S | -3.15 | 0.71 | 0.00 |
| Y | 0.38 | 0.31 | -0.00 |
| kVBM | 0.38 | 0.31 | -0.00 |
| xx | yy | xy | |
| Band gap [eV] | 0.56 | -0.02 | -0.00 |
| DCB [eV] | xx | yy | xy |
| Γ | -3.38 | 0.67 | 0.00 |
| X | -1.73 | -0.07 | -0.00 |
| S | -1.25 | 0.63 | 0.00 |
| Y | -3.77 | 0.31 | -0.00 |
| kCBM | 0.95 | 0.29 | -0.00 |
| Cij (N/m) | xx | yy | xy |
| xx | 23.00 | 0.34 | 0.00 |
| yy | 1.01 | 4.99 | 0.00 |
| xy | 0.00 | 0.00 | 2.92 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 2.92 N/m |
| Eigenvalue 1 | 4.97 N/m |
| Eigenvalue 2 | 23.02 N/m |
| cij [e/Å] | xx | yy | xy |
| x | 0.00 | 0.00 | 0.00 |
| y | 0.00 | 0.00 | 0.00 |
| z | 0.00 | 0.00 | -0.00 |
| cijclamped [e/Å] | xx | yy | xy |
| x | 0.00 | -0.00 | 0.00 |
| y | -0.00 | 0.00 | -0.00 |
| z | 0.00 | 0.00 | 0.00 |
| Key values [eV] | |
|---|---|
| Band gap (PBE) | 0.750 |
| Direct band gap (PBE) | 1.191 |
| Valence band maximum wrt. vacuum (PBE) | -5.755 |
| Conduction band minimum wrt. vacuum (PBE) | -5.005 |
| Key values [eV] | |
|---|---|
| Band gap (HSE06) | 1.179 |
| Direct band gap (HSE06) | 1.599 |
| Valence band maximum wrt. vacuum (HSE06) | -6.229 |
| Conduction band minimum wrt. vacuum (HSE06) | -5.050 |
| Property (VBM) | Value |
|---|---|
| Min eff. mass | 0.98 m0 |
| Max eff. mass | 1.04 m0 |
| DOS eff. mass | 1.01 m0 |
| Crystal coordinates | [0.000, 0.500] |
| Warping parameter | -0.000 |
| Barrier height | > 35.6 meV |
| Distance to barrier | > 0.0166 Å-1 |
| Property (CBM) | Value |
|---|---|
| Min eff. mass | 0.33 m0 |
| Max eff. mass | 2.32 m0 |
| DOS eff. mass | 0.87 m0 |
| Crystal coordinates | [0.255, -0.000] |
| Warping parameter | 0.000 |
| Barrier height | > 16.9 meV |
| Distance to barrier | > 0.0167 Å-1 |
| ZAgij | ux | uy | uz |
| Px | 0.17 | -0.00 | 0.00 |
| Py | 0.00 | 0.56 | 0.30 |
| Pz | 0.00 | 0.07 | 0.06 |
| ZAgij | ux | uy | uz |
| Px | 3.35 | 0.00 | 0.00 |
| Py | -0.00 | 0.25 | -0.33 |
| Pz | -0.00 | -0.06 | 0.01 |
| ZSeij | ux | uy | uz |
| Px | -1.76 | 0.00 | -0.00 |
| Py | -0.00 | -0.40 | 0.01 |
| Pz | -0.00 | -0.01 | -0.04 |
| ZSeij | ux | uy | uz |
| Px | -1.76 | -0.00 | 0.00 |
| Py | -0.00 | -0.41 | 0.01 |
| Pz | 0.00 | -0.01 | -0.04 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | Ag | 0.20 |
| 1 | Se | -0.25 |
| 2 | Ag | 0.30 |
| 3 | Se | -0.25 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 5.917 |
| Interband polarizability (y) [Å] | 2.100 |
| Interband polarizability (z) [Å] | 0.322 |
| Plasma frequency (x) [eV Å0.5] | 0.000 |
| Plasma frequency (y) [eV Å0.5] | 0.000 |
| Static polarizability [Å] | |
|---|---|
| Phonons only (x) | 0.57 |
| Phonons only (y) | 0.03 |
| Phonons only (z) | 0.00 |
| Total (phonons + electrons) (x) | 6.49 |
| Total (phonons + electrons) (y) | 2.13 |
| Total (phonons + electrons) (z) | 0.32 |
| Exciton binding energy (BSE) [eV] | 1.09 |
| Element | Relations |
|---|---|
| xxy | xxy=xyx |
| xxz | xxz=xzx |
| yxx | |
| yyy | |
| yyz | yyz=yzy |
| yzz | |
| Others | 0=xxx=xyy=xyz=xzy=xzz=yxy=yxz=yyx=yzx=zxy=zxz=zyx= zzx |
| zxx | |
| zyy | |
| zyz | zyz=zzy |
| zzz |
| Mode | Frequency (1/cm) | Degeneracy |
|---|---|---|
| Mode 1 | 0.3 | 3 |
| Mode 2 | 49.7 | 1 |
| Mode 3 | 52. | 1 |
| Mode 4 | 92.2 | 1 |
| Mode 5 | 154.3 | 1 |
| Mode 6 | 159.6 | 1 |
| Mode 7 | 167.1 | 1 |
| Mode 8 | 238.9 | 1 |
| Mode 9 | 242.1 | 1 |
| Mode 10 | 248.1 | 1 |
| Miscellaneous details | |
|---|---|
| Unique ID | 2AgSe-1 |
| Number of atoms | 4 |
| Number of species | 2 |
| Formula | Ag2Se2 |
| Reduced formula | AgSe |
| Stoichiometry | AB |
| Unit cell area [Å2] | 22.760 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/tree/AB/AgSe/Ag2Se2-248fffac5959 |
| Old uid | Ag2Se2-248fffac5959 |
| Space group (bulk in AA-stacking) | P2/m |
| Space group number (bulk in AA-stacking) | 10 |
| Point group | 2/m |
| Inversion symmetry | Yes |
| Layer group number | 14 |
| Layer group | p2/m11 |
| 2D Bravais type | Rectangular (op) |
| Thickness [Å] | 2.760 |
| Structure origin | original03-18 |
| Band gap (PBE) [eV] | 0.750 |
| Direct band gap (PBE) [eV] | 1.191 |
| gap_dir_nosoc | 1.214 |
| Vacuum level [eV] | 2.421 |
| Fermi level wrt. vacuum (PBE) [eV] | -5.380 |
| Valence band maximum wrt. vacuum (PBE) [eV] | -5.755 |
| Conduction band minimum wrt. vacuum (PBE) [eV] | -5.005 |
| minhessianeig | -0.000 |
| Miscellaneous details | |
|---|---|
| Dynamically stable | Yes |
| Band gap (HSE06) [eV] | 1.179 |
| Direct band gap (HSE06) [eV] | 1.599 |
| Fermi level wrt. vacuum (HSE) [eV] | -5.639 |
| Valence band maximum wrt. vacuum (HSE06) [eV] | -6.229 |
| Conduction band minimum wrt. vacuum (HSE06) [eV] | -5.050 |
| E_B | 1.091 |
| Interband polarizability (x) [Å] | 5.917 |
| Interband polarizability (y) [Å] | 2.100 |
| Interband polarizability (z) [Å] | 0.322 |
| Static polarizability (phonons) (x) [Å] | 0.571 |
| Static polarizability (phonons + electrons) (x) [Å] | 6.488 |
| Static polarizability (phonons) (y) [Å] | 0.032 |
| Static polarizability (phonons + electrons) (y) [Å] | 2.132 |
| Static polarizability (phonons) (z) [Å] | 0.001 |
| Static polarizability (phonons + electrons) (z) [Å] | 0.324 |
| Plasma frequency (x) [eV Å0.5] | 0.000 |
| Plasma frequency (y) [eV Å0.5] | 0.000 |
| Energy [eV] | -12.556 |
| 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] | 0.089 |
| Heat of formation [eV/atom] | 0.022 |
