1TiBr2-1

Atoms: TiBr₂ Convex hull Stiffness tensor Phonons Deformation potentials Band structure and DOS Effective masses Electronic band structure (HSE06@PBE) Electronic band structure (G₀W₀@PBE) Born charges Second harmonic generation Optical polarizability Infrared polarizability Raman spectrum Optical absorption (BSE and RPA) Bader charges Piezoelectric tensor Shift current Miscellaneous

Structure info
Layer group	p-6m2
Layer group number	78
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.033
Heat of formation [eV/atom]	-1.145
Dynamically stable	Yes

Basic properties
Magnetic state	NM
Band gap [eV]	0.758
Band gap (HSE06) [eV]	1.166
Band gap (G₀W₀) [eV]	1.421

Repeat: Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	3.472	0.000	0.000	Yes
2	-1.736	3.007	0.000	Yes
3	0.000	0.000	18.388	No

Lengths [Å]	3.472	3.472	18.388
Angles [°]	90.000	90.000	120.000

TiBr₂ (1TiBr2-1)
Heat of formation [eV/atom]	-1.14
Energy above convex hull [eV/atom]	0.03

Monolayers from C2DB
Ti₂Br₆, (2TiBr3-1)	-1.26 eV/atom
Ti₂Br₆, (2TiBr3-2)	-1.19 eV/atom
Ti₂Br₆, (2TiBr3-3)	-1.19 eV/atom
Ti₂Br₄, (2TiBr2-1)	-1.18 eV/atom
TiBr₂, (1TiBr2-1)	-1.14 eV/atom
TiBr₂, (1TiBr2-2)	-1.08 eV/atom
TiBr₂, (1TiBr2-3)	-0.86 eV/atom
Br₂Ti₂, (2BrTi-1)	-0.60 eV/atom
Br₂Ti₂, (2BrTi-2)	-0.38 eV/atom

Bulk crystals from OQMD123
Br₁₆Ti₄	-1.24 eV/atom
Br₆Ti₂	-1.24 eV/atom
Br₄	0.00 eV/atom
Ti₃	0.00 eV/atom

C_ij (N/m)	xx	yy	xy
xx	73.05	15.13	0.00
yy	15.01	73.19	0.00
xy	0.00	0.00	58.56

Stiffness tensor eigenvalues
Eigenvalue 0	58.05 N/m
Eigenvalue 1	58.56 N/m
Eigenvalue 2	88.19 N/m

Property	Value
Minimum eigenvalue of Hessian [eV/Å²]	-0.00

D_VB (eV)	xx	yy	xy
Γ	1.32	1.32	0.01
M	-0.49	0.95	-1.17
K	-2.01	-1.99	0.02
k_VBM	-2.01	-1.99	0.02

	xx	yy	xy
Band Gap	1.16	1.02	0.13

D_CB (eV)	xx	yy	xy
Γ	-2.48	-2.49	0.02
M	-5.14	-4.56	-0.49
K	-4.92	-4.90	0.02
k_CBM	-0.85	-0.97	0.14

Property (VBM)	Value
Min eff. mass	0.59 m₀
Max eff. mass	0.59 m₀
DOS eff. mass	0.59 m₀
Crystal coordinates	[0.333, 0.333]
Warping parameter	-0.001
Barrier height	> 94.3 meV
Distance to barrier	> 0.0208 Å^-1

Property (CBM)	Value
Min eff. mass	1.22 m₀
Max eff. mass	2.31 m₀
DOS eff. mass	1.68 m₀
Crystal coordinates	[0.122, 0.122]
Warping parameter	0.001
Barrier height	> 26.8 meV
Distance to barrier	> 0.0208 Å^-1

Property	Value
KVP: Band gap (HSE06) [eV]	1.17
KVP: Direct band gap (HSE06) [eV]	1.28
Valence band maximum wrt. vacuum level (HSE06)	-3.56 eV
Conduction band minimum wrt. vacuum level (HSE06)	-2.39 eV

Property	Value
Band gap (G₀W₀) [eV]	1.42
Direct band gap (G₀W₀) [eV]	1.65
Valence band maximum wrt. vacuum level (G₀W₀)	-3.80 eV
Conduction band minimum wrt. vacuum level (G₀W₀)	-2.38 eV

Z^Ti_ij	u_x	u_y	u_z
P_x	0.36	-0.00	0.00
P_y	-0.00	0.36	-0.00
P_z	0.00	0.00	0.26

Z^Br_ij	u_x	u_y	u_z
P_x	-0.18	0.00	-0.00
P_y	0.00	-0.18	0.00
P_z	-0.00	-0.00	-0.13

Z^Br_ij	u_x	u_y	u_z
P_x	-0.18	0.00	0.00
P_y	0.00	-0.18	-0.00
P_z	0.00	0.00	-0.13

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

Properties
Static interband polarizability at (x) [Å]	7.814
Static interband polarizability at (y) [Å]	7.814
Static interband polarizability at (z) [Å]	0.385
Plasma frequency (x) [Å^0.5]	0.000
Plasma frequency (y) [Å^0.5]	0.000

Static polarizability	[Å]
Phonons only (x)	0.02
Phonons only (y)	0.02
Phonons only (z)	0.01
Total (phonons + electrons) (x)	7.84
Total (phonons + electrons) (y)	7.84
Total (phonons + electrons) (z)	0.39

Mode	Frequency (1/cm)	Degeneracy
Mode 1	0.	3
Mode 2	118.2	2
Mode 3	178.6	1
Mode 4	248.6	2
Mode 5	326.3	1

Property	Value
The exciton binding energy from the Bethe–Salpeter equation (BSE) [eV].	0.59

#	Chemical symbol	Charges [\|e\|]
0	Ti	1.26
1	Br	-0.63
2	Br	-0.63

c_ij (e/Å^dim-1)	xx	yy	xy
x	0.00	0.00	-0.05
y	-0.05	0.05	-0.00
z	0.00	-0.00	-0.00

c^clamped_ij (e/Å^dim-1)	xx	yy	xy
x	0.00	0.00	-0.07
y	-0.07	0.07	-0.00
z	0.00	0.00	0.00

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

Miscellaneous details
Unique ID	1TiBr2-1
Number of atoms	3
Number of species	2
Formula	TiBr₂
Reduced formula	TiBr₂
Stoichiometry	AB₂
Unit cell area [Å²]	10.440
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB2/TiBr2/TiBr2-57116f9a9a4e
Old uid	TiBr2-57116f9a9a4e
Inversion symmetry	No
Layer group	p-6m2
Layer group number	78
Structure origin	original03-18
Band gap [eV]	0.758
gap_dir	0.929
gap_dir_nosoc	0.967
Vacuum level [eV]	3.665
Fermi level [eV]	0.168
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	1.166
gap_dir_hse	1.282
vbm_hse	0.105
cbm_hse	1.270

Miscellaneous details
Band gap (G₀W₀) [eV]	1.421
gap_dir_gw	1.649
vbm_gw	-0.137
cbm_gw	1.284
E_B	0.591
Static interband polarizability at (x) [Å]	7.814
Static interband polarizability at (y) [Å]	7.814
Static interband polarizability at (z) [Å]	0.385
Static polarizability (phonons) (x) [Å]	0.021
Static polarizability (phonons + electrons) (x) [Å]	7.835
Static polarizability (phonons) (y) [Å]	0.021
Static polarizability (phonons + electrons) (y) [Å]	7.835
Static polarizability (phonons) (z) [Å]	0.007
Static polarizability (phonons + electrons) (z) [Å]	0.392
Plasma frequency (x) [Å^0.5]	0.000
Plasma frequency (y) [Å^0.5]	0.000
Energy [eV]	-13.294
Magnetic state	NM
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]	0.033
Heat of formation [eV/atom]	-1.145

Atoms: TiBr2

Convex hull

Stiffness tensor

Phonons

Deformation potentials

Band structure and DOS

Effective masses

Electronic band structure (HSE06@PBE)

Electronic band structure (G₀W₀@PBE)

Born charges

Second harmonic generation

Optical polarizability

Infrared polarizability

Raman spectrum

Optical absorption (BSE and RPA)

Bader charges

Piezoelectric tensor

Shift current

Miscellaneous