| Structure info | |
|---|---|
| Layer group | pm2_1n |
| Layer group number | 32 |
| Structure origin | original03-18 |
| COD id of parent bulk structure | COD 1527226 |
| Stability | |
|---|---|
| Energy above convex hull [eV/atom] | 0.043 |
| Heat of formation [eV/atom] | -0.415 |
| Dynamically stable | Yes |
| Basic properties | |
|---|---|
| Magnetic | No |
| Ferroelectric | Yes |
| Band gap (PBE) [eV] | 1.414 |
| Band gap (HSE06) [eV] | 1.987 |
| Band gap (G₀W₀) [eV] | 2.503 |
| Symmetries | |
|---|---|
| 2D Bravais type | Rectangular (op) |
| Layer group number | 32 |
| Layer group | pm2_1n |
| Space group number (bulk in AA-stacking) | 31 |
| Space group (bulk in AA-stacking) | Pmn2_1 |
| Point group | mm2 |
| Inversion symmetry | No |
| Structure data | |
|---|---|
| Formula | Sn2S2 |
| Stoichiometry | AB |
| Number of atoms | 4 |
| Unit cell area [Å2] | 17.575 |
| Thickness [Å] | 2.864 |
| S2Sn2 (2SSn-1) | |
|---|---|
| Heat of formation [eV/atom] | -0.41 |
| Energy above convex hull [eV/atom] | 0.04 |
| Monolayers from C2DB | |
|---|---|
| S4Sn4 (4SSn-1) | -0.42 eV/atom |
| S2Sn2, (2SSn-1) | -0.41 eV/atom |
| SnS2 (1SnS2-1) | -0.40 eV/atom |
| S2Sn2 (2SSn-2) | -0.40 eV/atom |
| Sn7S12 (1Sn7S12-1) | -0.38 eV/atom |
| Sn9S12 (3Sn3S4-1) | -0.37 eV/atom |
| Sn8S12 (4Sn2S3-1) | -0.36 eV/atom |
| SSn (1SSn-1) | -0.34 eV/atom |
| SnS2 (1SnS2-2) | -0.32 eV/atom |
| SnS2 (1SnS2-3) | -0.12 eV/atom |
| Sn2S4 (2SnS2-1) | -0.10 eV/atom |
| S2Sn2 (2SSn-3) | -0.10 eV/atom |
| Sn2S6 (2SnS3-1) | -0.08 eV/atom |
| S2Sn2 (2SSn-4) | -0.02 eV/atom |
| Sn4 (4Sn-1) | 0.26 eV/atom |
| Sn2 (2Sn-1) | 0.44 eV/atom |
| S2 (2S-1) | 0.45 eV/atom |
| S2 (2S-2) | 0.62 eV/atom |
| Minimum eigenvalue of Hessian [eV/Ų] | -0.00 |
| DVB [eV] | xx | yy | xy |
| Γ | -3.98 | -3.25 | 0.00 |
| X | -3.32 | -5.73 | -0.00 |
| S | 1.84 | 0.41 | -1.53 |
| Y | -6.27 | -0.98 | -0.00 |
| kVBM | -4.17 | -5.96 | -0.00 |
| xx | yy | xy | |
| Band gap [eV] | 1.68 | 9.61 | 0.00 |
| DCB [eV] | xx | yy | xy |
| Γ | 1.96 | 3.53 | 0.00 |
| X | -1.32 | -8.14 | 0.00 |
| S | -3.97 | -1.13 | -0.82 |
| Y | -3.29 | 3.39 | 0.00 |
| kCBM | -2.50 | 3.65 | 0.00 |
| Cij (N/m) | xx | yy | xy |
| xx | 17.37 | 14.73 | -0.02 |
| yy | 15.82 | 38.64 | -0.00 |
| xy | 0.00 | -0.00 | 31.29 |
| Stiffness tensor eigenvalues | |
| Eigenvalue 0 | 9.40 N/m |
| Eigenvalue 1 | 31.29 N/m |
| Eigenvalue 2 | 46.61 N/m |
| cij [e/Å] | xx | yy | xy |
| x | 0.96 | 0.11 | 0.00 |
| y | 0.00 | -0.00 | 0.77 |
| z | 0.00 | -0.00 | -0.00 |
| cijclamped [e/Å] | xx | yy | xy |
| x | 0.03 | -0.32 | 0.00 |
| y | 0.00 | -0.00 | -0.31 |
| z | 0.00 | -0.00 | 0.00 |
| Key values [eV] | |
|---|---|
| Band gap (PBE) | 1.414 |
| Direct band gap (PBE) | 1.587 |
| Valence band maximum wrt. vacuum (PBE) | -4.655 |
| Conduction band minimum wrt. vacuum (PBE) | -3.241 |
| Key values [eV] | |
|---|---|
| Band gap (HSE06) | 1.987 |
| Direct band gap (HSE06) | 2.170 |
| Valence band maximum wrt. vacuum (HSE06) | -5.022 |
| Conduction band minimum wrt. vacuum (HSE06) | -3.035 |
| Key values [eV] | |
|---|---|
| Band gap (G₀W₀) | 2.503 |
| Direct band gap (G₀W₀) | 2.665 |
| Valence band maximum wrt. vacuum (G₀W₀) | -5.561 |
| Conduction band minimum wrt. vacuum (G₀W₀) | -3.058 |
| Property (VBM) | Value |
|---|---|
| Min eff. mass | 0.22 m0 |
| Max eff. mass | 0.31 m0 |
| DOS eff. mass | 0.26 m0 |
| Crystal coordinates | [-0.391, -0.002] |
| Warping parameter | -0.000 |
| Barrier height | > 102.0 meV |
| Distance to barrier | > 0.0154 Å-1 |
| Property (CBM) | Value |
|---|---|
| Min eff. mass | 0.18 m0 |
| Max eff. mass | 0.21 m0 |
| DOS eff. mass | 0.20 m0 |
| Crystal coordinates | [0.000, -0.411] |
| Warping parameter | 0.000 |
| Barrier height | > 130.0 meV |
| Distance to barrier | > 0.0154 Å-1 |
| ZSij | ux | uy | uz |
| Px | -3.46 | -0.00 | -0.86 |
| Py | -0.00 | -3.89 | 0.00 |
| Pz | -0.09 | 0.00 | -0.41 |
| ZSnij | ux | uy | uz |
| Px | 3.46 | -0.00 | 0.36 |
| Py | -0.00 | 3.89 | -0.00 |
| Pz | -0.05 | 0.00 | 0.41 |
| ZSij | ux | uy | uz |
| Px | -3.46 | -0.00 | 0.86 |
| Py | -0.00 | -3.89 | 0.00 |
| Pz | 0.09 | 0.00 | -0.41 |
| ZSnij | ux | uy | uz |
| Px | 3.46 | 0.00 | -0.36 |
| Py | 0.00 | 3.89 | -0.00 |
| Pz | 0.05 | -0.00 | 0.41 |
| Atom No. | Chemical symbol | Charges [|e|] |
|---|---|---|
| 0 | S | -0.97 |
| 1 | S | -0.97 |
| 2 | Sn | 0.97 |
| 3 | Sn | 0.97 |
| Spontaneous polarization vector component [pC/m] | |
|---|---|
| Px | 292.113 |
| Py | -0.002 |
| Pz | -0.001 |
| Properties | |
|---|---|
| Interband polarizability (x) [Å] | 5.209 |
| Interband polarizability (y) [Å] | 5.306 |
| Interband polarizability (z) [Å] | 0.407 |
| Plasma frequency (x) [eV Å0.5] | 0.000 |
| Plasma frequency (y) [eV Å0.5] | 0.000 |
| Static polarizability [Å] | |
|---|---|
| Phonons only (x) | 11.69 |
| Phonons only (y) | 19.62 |
| Phonons only (z) | 0.04 |
| Total (phonons + electrons) (x) | 16.90 |
| Total (phonons + electrons) (y) | 24.93 |
| Total (phonons + electrons) (z) | 0.44 |
| Exciton binding energy (BSE) [eV] | 0.59 |
| Element | Relations |
|---|---|
| xxx | |
| xyy | |
| xzz | |
| yxy | yxy=yyx |
| Others | 0=yyy=xxz=xxy=xyz=xzx=xzy=yxx=yxz=xyx=yyz=yzx=yzy= yzz=zxx=zxy=zyx=zyy=zyz=zzy=zzz |
| zxz | zxz=zzx |
| Element | Relations |
|---|---|
| xxx | |
| xyy | |
| xzz | |
| yxy | yxy=yyx |
| Others | 0=yyy=xxz=xyx=xyz=xzx=xzy=yxx=yxz=xxy=yyz=yzx=yzy= yzz=zxx=zxy=zyx=zyy=zyz=zzy=zzz |
| zxz | zxz=zzx |
| Miscellaneous details | |
|---|---|
| Unique ID | 2SSn-1 |
| Number of atoms | 4 |
| Number of species | 2 |
| Formula | Sn2S2 |
| Reduced formula | SnS |
| Stoichiometry | AB |
| Unit cell area [Å2] | 17.575 |
| Original file-system folder | /home/niflheim2/cmr/C2DB-ASR/tree/AB/SSn/S2Sn2-7a8373382b33 |
| Old uid | S2Sn2-7a8373382b33 |
| Space group (bulk in AA-stacking) | Pmn2_1 |
| Space group number (bulk in AA-stacking) | 31 |
| Point group | mm2 |
| Inversion symmetry | No |
| Layer group number | 32 |
| Layer group | pm2_1n |
| 2D Bravais type | Rectangular (op) |
| Thickness [Å] | 2.864 |
| Structure origin | original03-18 |
| Band gap (PBE) [eV] | 1.414 |
| Direct band gap (PBE) [eV] | 1.587 |
| gap_dir_nosoc | 1.623 |
| Vacuum level [eV] | 3.313 |
| Fermi level wrt. vacuum (PBE) [eV] | -3.948 |
| Valence band maximum wrt. vacuum (PBE) [eV] | -4.655 |
| Conduction band minimum wrt. vacuum (PBE) [eV] | -3.241 |
| minhessianeig | -0.000 |
| Dynamically stable | Yes |
| Band gap (HSE06) [eV] | 1.987 |
| Direct band gap (HSE06) [eV] | 2.170 |
| Fermi level wrt. vacuum (HSE) [eV] | -4.028 |
| Miscellaneous details | |
|---|---|
| Valence band maximum wrt. vacuum (HSE06) [eV] | -5.022 |
| Conduction band minimum wrt. vacuum (HSE06) [eV] | -3.035 |
| Band gap (G₀W₀) [eV] | 2.503 |
| Direct band gap (G₀W₀) [eV] | 2.665 |
| Fermi level wrt. vacuum (G₀W₀) [eV] | -4.309 |
| Valence band maximum wrt. vacuum (G₀W₀) [eV] | -5.561 |
| Conduction band minimum wrt. vacuum (G₀W₀) [eV] | -3.058 |
| E_B | 0.589 |
| Interband polarizability (x) [Å] | 5.209 |
| Interband polarizability (y) [Å] | 5.306 |
| Interband polarizability (z) [Å] | 0.407 |
| Static polarizability (phonons) (x) [Å] | 11.691 |
| Static polarizability (phonons + electrons) (x) [Å] | 16.900 |
| Static polarizability (phonons) (y) [Å] | 19.625 |
| Static polarizability (phonons + electrons) (y) [Å] | 24.930 |
| Static polarizability (phonons) (z) [Å] | 0.037 |
| Static polarizability (phonons + electrons) (z) [Å] | 0.444 |
| Plasma frequency (x) [eV Å0.5] | 0.000 |
| Plasma frequency (y) [eV Å0.5] | 0.000 |
| Energy [eV] | -17.928 |
| COD id of parent bulk structure | COD 1527226 |
| Magnetic | No |
| 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] | 292.113 |
| Energy above convex hull [eV/atom] | 0.043 |
| Heat of formation [eV/atom] | -0.415 |
