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Structure info
Layer group pmmn
Layer group number 46
Structure origin original03-18
Stability
Energy above convex hull [eV/atom] 0.067
Heat of formation [eV/atom] -0.938
Dynamically stable Yes
Basic properties
Magnetic No
Band gap [eV] 1.535
Band gap (HSE06) [eV] 2.322
XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 5.235 -0.000 0.000 Yes
2 -0.000 3.615 0.000 Yes
3 -0.000 0.000 21.342 No
Lengths [Å] 5.235 3.615 21.342
Angles [°] 90.000 90.000 90.000

Symmetries
2D Bravais type Rectangular (op)
Layer group number 46
Layer group pmmn
Space group number (bulk in AA-stacking) 59
Space group (bulk in AA-stacking) Pmmn
Point group mmm
Inversion symmetry Yes
Structure data
Formula Al2Br2Se2
Stoichiometry ABC
Number of atoms 6
Unit cell area [Å2] 18.924
Thickness [Å] 5.623

Al2Br2Se2 (2AlBrSe-2)
Heat of formation [eV/atom] -0.94
Energy above convex hull [eV/atom] 0.07
Monolayers from C2DB
Al2Br6 (2AlBr3-1) -1.12 eV/atom
Al2Br6 (2AlBr3-2) -1.04 eV/atom
Al4Br4Se4 (4AlBrSe-1) -1.00 eV/atom
Al2Br2Se2 (2AlBrSe-1) -1.00 eV/atom
Al2Br2Se2, (2AlBrSe-2) -0.94 eV/atom
Al2Br6 (2AlBr3-3) -0.93 eV/atom
Al8Se12 (4Al2Se3-1) -0.86 eV/atom
Al4Se6 (2Al2Se3-1) -0.84 eV/atom
Al4Se6 (2Al2Se3-2) -0.83 eV/atom
Al4Se6 (2Al2Se3-3) -0.81 eV/atom
Al2Se3 (1Al2Se3-1) -0.79 eV/atom
Al6Se9 (3Al2Se3-1) -0.77 eV/atom
Al2Se3 (1Al2Se3-2) -0.77 eV/atom
Al2Br4 (2AlBr2-1) -0.74 eV/atom
Al3Se4 (1Al3Se4-1) -0.72 eV/atom
Al2Se2 (2AlSe-1) -0.72 eV/atom
Al2Se2 (2AlSe-2) -0.71 eV/atom
Al2Se2 (2AlSe-3) -0.69 eV/atom
AlBr2 (1AlBr2-1) -0.64 eV/atom
AlSeBr2 (1AlSeBr2-1) -0.61 eV/atom
Al2Se5 (1Al2Se5-1) -0.60 eV/atom
AlBr2 (1AlBr2-2) -0.59 eV/atom
Al2Se4 (2AlSe2-1) -0.55 eV/atom
AlSe2 (1AlSe2-1) -0.55 eV/atom
AlBr2 (1AlBr2-3) -0.46 eV/atom
Al2Br2 (2AlBr-1) -0.42 eV/atom
Al2Se2 (2AlSe-4) -0.36 eV/atom
Al2Se4 (2AlSe2-2) -0.31 eV/atom
Al2Se2 (2AlSe-5) -0.14 eV/atom
AlSe4 (1AlSe4-1) -0.13 eV/atom
Se2Br5 (1Se2Br5-1) -0.06 eV/atom
Al2Br2 (2AlBr-2) -0.04 eV/atom
Se2 (2Se-1) 0.21 eV/atom
Se2 (2Se-2) 0.29 eV/atom
Bulk crystals from OQMD123
Al4Br12 -1.13 eV/atom
Al4Se6 -0.84 eV/atom
Al2Br14Se2 -0.63 eV/atom
Br8Se8 -0.10 eV/atom
Al 0.00 eV/atom
Br4 0.00 eV/atom
Se3 0.00 eV/atom

ABC/2AlBrSe/2/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

DVB [eV] xx yy xy
Γ -4.52 -10.29 -0.00
X -1.95 -10.77 0.00
S -0.44 -1.57 -3.29
Y 1.75 0.60 -0.00
kVBM -4.52 -10.29 -0.00
xx yy xy
Band gap [eV] 3.77 8.49 0.00
DCB [eV] xx yy xy
Γ 0.64 -13.13 0.00
X -1.52 -11.55 -0.00
S -1.31 -3.70 3.12
Y 0.44 -3.29 -0.00
kCBM -0.76 -1.80 0.00

Cij (N/m) xx yy xy
xx 54.68 13.60 0.00
yy 10.70 94.81 0.00
xy 0.00 0.00 55.16
Stiffness tensor eigenvalues
Eigenvalue 0 51.33 N/m
Eigenvalue 1 55.16 N/m
Eigenvalue 2 98.16 N/m

DOS BZ

Details
Band gap (HSE06) [eV] 2.322
Direct band gap (HSE06) [eV] 2.416
Valence band maximum wrt. vacuum level (HSE06) [eV] -5.956
Conduction band minimum vs. vacuum (HSE06) [eV] -3.633

VBM
Property (VBM) Value
Min eff. mass 0.20 m0
Max eff. mass 0.75 m0
DOS eff. mass 0.39 m0
Crystal coordinates [-0.000, -0.000]
Warping parameter -0.000
Barrier height > 102.6 meV
Distance to barrier > 0.0231 Å-1
CBM
Property (CBM) Value
Min eff. mass 0.46 m0
Max eff. mass 1.06 m0
DOS eff. mass 0.70 m0
Crystal coordinates [-0.000, -0.433]
Warping parameter 0.000
Barrier height > 72.9 meV
Distance to barrier > 0.0232 Å-1

ZAlij ux uy uz
Px 4.18 -0.00 -0.00
Py -0.00 3.37 -0.00
Pz 0.00 -0.00 0.71
ZSeij ux uy uz
Px -3.34 0.00 -0.00
Py -0.00 -1.78 0.00
Pz 0.00 -0.00 -0.29
ZBrij ux uy uz
Px -0.84 0.00 0.00
Py 0.00 -1.58 -0.00
Pz 0.00 -0.00 -0.42
ZAlij ux uy uz
Px 4.18 -0.00 0.00
Py -0.00 3.37 -0.00
Pz 0.00 -0.00 0.71
ZSeij ux uy uz
Px -3.34 -0.00 0.00
Py -0.00 -1.78 -0.00
Pz 0.00 -0.00 -0.29
ZBrij ux uy uz
Px -0.84 -0.00 -0.00
Py 0.00 -1.58 -0.00
Pz 0.00 0.00 -0.42

Atom No. Chemical symbol Charges [|e|]
0 Al 2.12
1 Al 2.12
2 Se -1.37
3 Se -1.37
4 Br -0.75
5 Br -0.75

ABC/2AlBrSe/2/rpa-pol-x.png ABC/2AlBrSe/2/rpa-pol-z.png
ABC/2AlBrSe/2/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 3.129
Interband polarizability (y) [Å] 2.884
Interband polarizability (z) [Å] 0.482
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000

ABC/2AlBrSe/2/ir-pol-x.png ABC/2AlBrSe/2/ir-pol-z.png
ABC/2AlBrSe/2/ir-pol-y.png
Static polarizability [Å]
Phonons only (x) 14.63
Phonons only (y) 3.86
Phonons only (z) 0.06
Total (phonons + electrons) (x) 17.76
Total (phonons + electrons) (y) 6.74
Total (phonons + electrons) (z) 0.55

ABC/2AlBrSe/2/Raman.png
Mode Frequency (1/cm) Degeneracy
Mode 1 0. 3
Mode 2 64. 1
Mode 3 66. 1
Mode 4 86.3 1
Mode 5 88.7 1
Mode 6 94.2 1
Mode 7 107.8 1
Mode 8 119.8 1
Mode 9 166.5 1
Mode 10 178. 2
Mode 11 241.2 1
Mode 12 265. 1
Mode 13 268.8 1
Mode 14 372.4 1
Mode 15 400.4 1

Miscellaneous details
Unique ID 2AlBrSe-2
Number of atoms 6
Number of species 3
Formula Al2Br2Se2
Reduced formula AlBrSe
Stoichiometry ABC
Unit cell area [Å2] 18.924
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/ABC/AlBrSe/Al2Br2Se2-1b6ba48355c2
Old uid Al2Br2Se2-1b6ba48355c2
Space group (bulk in AA-stacking) Pmmn
Space group number (bulk in AA-stacking) 59
Point group mmm
Inversion symmetry Yes
Layer group number 46
Layer group pmmn
2D Bravais type Rectangular (op)
Thickness [Å] 5.623
Structure origin original03-18
Band gap [eV] 1.535
gap_dir 1.642
gap_dir_nosoc 1.649
Vacuum level [eV] 3.466
Fermi level [eV] -1.214
minhessianeig -0.000
Miscellaneous details
Dynamically stable Yes
Band gap (HSE06) [eV] 2.322
Direct band gap (HSE06) [eV] 2.416
Valence band maximum wrt. vacuum level (HSE06) [eV] -5.956
Conduction band minimum vs. vacuum (HSE06) [eV] -3.633
Interband polarizability (x) [Å] 3.129
Interband polarizability (y) [Å] 2.884
Interband polarizability (z) [Å] 0.482
Static polarizability (phonons) (x) [Å] 14.630
Static polarizability (phonons + electrons) (x) [Å] 17.759
Static polarizability (phonons) (y) [Å] 3.860
Static polarizability (phonons + electrons) (y) [Å] 6.744
Static polarizability (phonons) (z) [Å] 0.065
Static polarizability (phonons + electrons) (z) [Å] 0.547
Plasma frequency (x) [eV Å0.5] 0.000
Plasma frequency (y) [eV Å0.5] 0.000
Energy [eV] -23.239
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] 0.067
Heat of formation [eV/atom] -0.938