C2DB-logo

Structure info
Layer group p2_111
Layer group number 9
Structure origin original03-18
Stability
Energy above convex hull [eV/atom] 0.000
Heat of formation [eV/atom] -0.184
Dynamically stable Yes
Basic properties
Magnetic No
Ferroelectric Yes
Band gap [eV] 1.237
Band gap (HSE06) [eV] 2.262
XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 5.278 0.000 0.000 Yes
2 0.000 8.245 0.000 Yes
3 0.000 0.000 18.170 No
Lengths [Å] 5.278 8.245 18.170
Angles [°] 90.000 90.000 90.000

Symmetries
2D Bravais type Rectangular (op)
Layer group number 9
Layer group p2_111
Space group number (bulk in AA-stacking) 4
Space group (bulk in AA-stacking) P2_1
Point group 2
Inversion symmetry No
Structure data
Formula Ag2Br2Se4
Stoichiometry ABC2
Number of atoms 8
Unit cell area [Å2] 43.519
Thickness [Å] 3.622

Ag2Br2Se4 (2AgBrSe2-1)
Heat of formation [eV/atom] -0.18
Energy above convex hull [eV/atom] 0.00
Monolayers from C2DB
Ag4Br4 (4AgBr-1) -0.35 eV/atom
Ag4Br4 (4AgBr-2) -0.34 eV/atom
Ag6Br6 (6AgBr-1) -0.34 eV/atom
Ag2Br2 (2AgBr-1) -0.34 eV/atom
Ag2Br2 (2AgBr-2) -0.34 eV/atom
Ag6Br6 (6AgBr-2) -0.34 eV/atom
Ag6Br6 (6AgBr-3) -0.33 eV/atom
Ag2Br2 (2AgBr-3) -0.33 eV/atom
Ag5Br5 (5AgBr-1) -0.33 eV/atom
Ag6Br6 (6AgBr-4) -0.32 eV/atom
Ag8Br8 (8AgBr-1) -0.32 eV/atom
Ag12Br12 (12AgBr-1) -0.32 eV/atom
Ag3Br3 (3AgBr-1) -0.32 eV/atom
Ag2Br2 (2AgBr-4) -0.31 eV/atom
Ag3Br3 (3AgBr-2) -0.31 eV/atom
Ag3Br3 (3AgBr-3) -0.31 eV/atom
Ag2Br2 (2AgBr-5) -0.30 eV/atom
Ag3Br3 (3AgBr-4) -0.30 eV/atom
Ag8Br8 (8AgBr-2) -0.30 eV/atom
Ag8Br8 (8AgBr-3) -0.30 eV/atom
Ag6Br6 (6AgBr-5) -0.30 eV/atom
AgBr (1AgBr-1) -0.30 eV/atom
Ag2Br2 (2AgBr-6) -0.29 eV/atom
Ag2Br4 (2AgBr2-1) -0.24 eV/atom
Ag4Br8 (4AgBr2-1) -0.24 eV/atom
Ag6Br12 (6AgBr2-1) -0.23 eV/atom
Ag2Br4 (2AgBr2-2) -0.20 eV/atom
AgBr2 (1AgBr2-1) -0.19 eV/atom
Ag2Br6 (2AgBr3-1) -0.19 eV/atom
Ag2Br6 (2AgBr3-2) -0.19 eV/atom
Ag4Br8 (4AgBr2-2) -0.19 eV/atom
Ag2Br2Se4, (2AgBrSe2-1) -0.18 eV/atom
Ag2Br2Se4 (2AgBrSe2-2) -0.18 eV/atom
Ag2Br6 (2AgBr3-3) -0.18 eV/atom
Ag4Br4Se4 (4AgBrSe-1) -0.17 eV/atom
Ag4Br12 (4AgBr3-1) -0.16 eV/atom
AgBr3 (1AgBr3-1) -0.16 eV/atom
Ag2Br6 (2AgBr3-4) -0.15 eV/atom
AgBr2 (1AgBr2-2) -0.13 eV/atom
AgBr2 (1AgBr2-3) -0.09 eV/atom
Se2Ag4 (2SeAg2-1) -0.09 eV/atom
Se8Ag16 (8SeAg2-1) -0.07 eV/atom
Se2Br5 (1Se2Br5-1) -0.06 eV/atom
Ag2Br6 (2AgBr3-5) -0.06 eV/atom
Ag2Br2Se2 (2AgBrSe-1) -0.03 eV/atom
Ag4Se4 (4AgSe-1) -0.02 eV/atom
Ag2Br6 (2AgBr3-6) 0.01 eV/atom
Ag2Se2 (2AgSe-1) 0.02 eV/atom
AgSeBr2 (1AgSeBr2-1) 0.03 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
Bulk crystals from OQMD123
AgBr -0.32 eV/atom
Ag4Br6 -0.28 eV/atom
Br8Se8 -0.10 eV/atom
Ag8Se4 -0.07 eV/atom
Ag4 0.00 eV/atom
Br4 0.00 eV/atom
Se3 0.00 eV/atom

ABC2/2AgBrSe2/1/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

DVB [eV] xx yy xy
Γ 0.53 2.56 -0.02
X -2.54 -1.32 -0.03
S -0.40 -0.20 -0.02
Y -0.70 -1.59 -0.03
kVBM -0.70 -1.59 -0.03
xx yy xy
Band gap [eV] -2.71 0.24 -0.05
DCB [eV] xx yy xy
Γ -0.32 0.42 -0.09
X -2.23 -0.66 -0.07
S -2.51 -1.08 -0.06
Y -3.41 -1.35 -0.08
kCBM -3.41 -1.35 -0.08

Cij (N/m) xx yy xy
xx 10.11 1.41 -0.20
yy 2.07 7.42 -0.36
xy -0.77 -0.43 5.46
Stiffness tensor eigenvalues
Eigenvalue 0 5.39 N/m
Eigenvalue 1 6.61 N/m
Eigenvalue 2 10.99 N/m

cij [e/Å] xx yy xy
x 0.02 -0.04 0.00
y -0.00 -0.01 -0.04
z 0.00 0.00 0.02
cijclamped [e/Å] xx yy xy
x -0.02 0.02 -0.00
y -0.00 0.00 0.02
z 0.00 -0.00 -0.00

DOS BZ

Details
Band gap (HSE06) [eV] 2.262
Direct band gap (HSE06) [eV] 2.267
Valence band maximum wrt. vacuum level (HSE06) [eV] -6.831
Conduction band minimum vs. vacuum (HSE06) [eV] -4.569

VBM
Property (VBM) Value
Min eff. mass 0.86 m0
Max eff. mass 1.16 m0
DOS eff. mass 1.02 m0
Crystal coordinates [0.012, 0.500]
Warping parameter -0.005
Barrier height > 8.4 meV
Distance to barrier > 0.0118 Å-1
CBM
Property (CBM) Value
Min eff. mass 0.66 m0
Max eff. mass 1.94 m0
DOS eff. mass 1.13 m0
Crystal coordinates [0.001, 0.432]
Warping parameter 0.000
Barrier height > 5.6 meV
Distance to barrier > 0.0125 Å-1

ZBrij ux uy uz
Px -1.34 0.14 0.12
Py 0.09 -1.90 0.02
Pz -0.00 -0.02 -0.39
ZSeij ux uy uz
Px -0.06 -0.07 -0.15
Py 0.12 -0.10 0.49
Pz 0.03 0.05 0.03
ZSeij ux uy uz
Px 0.51 -0.78 -0.21
Py -0.77 0.88 -0.23
Pz -0.00 0.01 0.05
ZAgij ux uy uz
Px 0.88 0.08 -0.67
Py 0.12 1.13 -0.26
Pz -0.13 -0.03 0.30
ZBrij ux uy uz
Px -1.33 -0.13 -0.12
Py -0.09 -1.90 0.02
Pz 0.00 -0.02 -0.39
ZSeij ux uy uz
Px -0.06 0.07 0.15
Py -0.12 -0.12 0.48
Pz -0.03 0.05 0.03
ZSeij ux uy uz
Px 0.52 0.76 0.20
Py 0.76 0.87 -0.24
Pz 0.00 0.01 0.05
ZAgij ux uy uz
Px 0.89 -0.07 0.68
Py -0.11 1.13 -0.27
Pz 0.13 -0.03 0.30

Atom No. Chemical symbol Charges [|e|]
0 Br -0.48
1 Br -0.48
2 Se 0.04
3 Se 0.03
4 Se 0.09
5 Se 0.09
6 Ag 0.36
7 Ag 0.36

Spontaneous polarization vector component [pC/m] Value
Px -126.28
Py -0.06
Pz -0.00

ABC2/2AgBrSe2/1/rpa-pol-x.png ABC2/2AgBrSe2/1/rpa-pol-z.png
ABC2/2AgBrSe2/1/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 2.593
Interband polarizability (y) [Å] 2.399
Interband polarizability (z) [Å] 0.329

ABC2/2AgBrSe2/1/ir-pol-x.png ABC2/2AgBrSe2/1/ir-pol-z.png
ABC2/2AgBrSe2/1/ir-pol-y.png
Static polarizability [Å]
Phonons only (x) 2.66
Phonons only (y) 3.76
Phonons only (z) 0.05
Total (phonons + electrons) (x) 5.26
Total (phonons + electrons) (y) 6.16
Total (phonons + electrons) (z) 0.38

Shift-current Shift-current Shift-current Shift-current
Element Relations
xxx
xyy
xyz xyz=xzy
xzz
yxy yxy=yyx
yxz yxz=yzx
Others 0=yyy=xxz=xyx=xzx=yxx=xxy=yyz=yzy=yzz=zxx=zyy=zyz= zzy=zzz
zxy zxy=zyx
zxz zxz=zzx
Shift-current Shift-current Shift-current Shift-current

Miscellaneous details
Unique ID 2AgBrSe2-1
Number of atoms 8
Number of species 3
Formula Ag2Br2Se4
Reduced formula AgBrSe2
Stoichiometry ABC2
Unit cell area [Å2] 43.519
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree/ABC2/AgBrSe2/Ag2Br2Se4-c7e3d505588c
Old uid Ag2Br2Se4-c7e3d505588c
Space group (bulk in AA-stacking) P2_1
Space group number (bulk in AA-stacking) 4
Point group 2
Inversion symmetry No
Layer group number 9
Layer group p2_111
2D Bravais type Rectangular (op)
Thickness [Å] 3.622
Structure origin original03-18
Band gap [eV] 1.237
gap_dir 1.243
gap_dir_nosoc 1.297
Vacuum level [eV] 2.575
Fermi level [eV] -2.789
minhessianeig -0.000
Miscellaneous details
Dynamically stable Yes
Band gap (HSE06) [eV] 2.262
Direct band gap (HSE06) [eV] 2.267
Valence band maximum wrt. vacuum level (HSE06) [eV] -6.831
Conduction band minimum vs. vacuum (HSE06) [eV] -4.569
Interband polarizability (x) [Å] 2.593
Interband polarizability (y) [Å] 2.399
Interband polarizability (z) [Å] 0.329
Static polarizability (phonons) (x) [Å] 2.664
Static polarizability (phonons + electrons) (x) [Å] 5.257
Static polarizability (phonons) (y) [Å] 3.763
Static polarizability (phonons + electrons) (y) [Å] 6.161
Static polarizability (phonons) (z) [Å] 0.054
Static polarizability (phonons + electrons) (z) [Å] 0.384
Energy [eV] -24.254
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] 126.278
Energy above convex hull [eV/atom] 0.000
Heat of formation [eV/atom] -0.184