Atoms: Ga₂Se₂

Structure info
Layer group	p-3m1
Layer group number	72
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.004
Heat of formation [eV/atom]	-0.598
Dynamically stable	Yes

Basic properties
Magnetic state	NM
Band gap [eV]	1.644
Band gap (HSE06) [eV]	2.371
Band gap (G₀W₀) [eV]	3.331

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	3.835	0.000	0.000	Yes
2	-1.918	3.321	0.000	Yes
3	0.000	0.000	20.807	No

Lengths [Å]	3.835	3.835	20.807
Angles [°]	90.000	90.000	120.000

Convex hull

Ga2Se2 (2GaSe-2)
Heat of formation [eV/atom]	-0.60
Energy above convex hull [eV/atom]	0.00

Monolayers from C2DB
Ga2Se2, (2GaSe-1)	-0.60 eV/atom
Ga2Se2, (2GaSe-2)	-0.60 eV/atom
Ga8Se12, (4Ga2Se3-1)	-0.59 eV/atom
Ga2Se2, (2GaSe-3)	-0.55 eV/atom
Ga2Se3, (1Ga2Se3-1)	-0.53 eV/atom
Se12Ga13, (1Se12Ga13-1)	-0.53 eV/atom
Ga4Se6, (2Ga2Se3-1)	-0.53 eV/atom
Ga4Se6, (2Ga2Se3-2)	-0.52 eV/atom
Ga3Se4, (1Ga3Se4-1)	-0.47 eV/atom
Se12Ga14, (2Se6Ga7-1)	-0.47 eV/atom
Ga2Se3, (1Ga2Se3-2)	-0.45 eV/atom
Se12Ga15, (3Se4Ga5-1)	-0.45 eV/atom
Ga2Se5, (1Ga2Se5-1)	-0.42 eV/atom
Ga2Se2, (2GaSe-4)	-0.37 eV/atom
GaSe2, (1GaSe2-1)	-0.34 eV/atom
Ga2Se2, (2GaSe-5)	-0.30 eV/atom
Ga2Se4, (2GaSe2-1)	-0.24 eV/atom
Ga2Se4, (2GaSe2-2)	-0.23 eV/atom
Ga2Se2, (2GaSe-6)	-0.19 eV/atom
Ga2Se2, (2GaSe-7)	-0.17 eV/atom
Ga2Se4, (2GaSe2-3)	-0.03 eV/atom
GaSe4, (1GaSe4-1)	-0.02 eV/atom
Ga4, (4Ga-1)	0.16 eV/atom
Se2, (2Se-1)	0.21 eV/atom
Se2, (2Se-2)	0.29 eV/atom

Bulk crystals from OQMD123
Ga4Se4	-0.60 eV/atom
Ga4Se6	-0.59 eV/atom
Ga4	0.00 eV/atom
Se3	0.00 eV/atom

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	67.87	13.87	-0.02
yy	13.74	67.91	-0.01
xy	0.01	-0.01	55.23

Stiffness tensor eigenvalues
Eigenvalue 0	54.08 N/m
Eigenvalue 1	55.23 N/m
Eigenvalue 2	81.70 N/m

Phonons

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

Deformation potentials

DVB (eV)	xx	yy	xy
Γ	1.71	1.69	-0.00
M	0.83	1.72	-0.58
K	1.07	1.05	-0.00
kVBM	2.12	2.40	0.06

	xx	yy	xy
Band Gap	-10.98	-11.26	-0.06

DCB (eV)	xx	yy	xy
Γ	-8.86	-8.86	-0.00
M	0.05	-5.31	4.75
K	-0.09	-0.07	0.00
kCBM	-8.86	-8.86	-0.00

Band structure and DOS

Effective masses

Property (VBM)	Value
Min eff. mass	1.91 m0
Max eff. mass	9.98 m0
DOS eff. mass	4.36 m0
Crystal coordinates	[0.072, 0.072]
Warping parameter	-0.000
Barrier height	> 2.1 meV
Distance to barrier	> 0.0203 Å-1

Property (CBM)	Value
Min eff. mass	0.17 m0
Max eff. mass	0.17 m0
DOS eff. mass	0.17 m0
Crystal coordinates	[0.000, 0.000]
Warping parameter	0.000
Barrier height	> 301.4 meV
Distance to barrier	> 0.0188 Å-1

Electronic band structure (HSE06@PBE)

Property	Value
KVP: Band gap (HSE06) [eV]	2.37
KVP: Direct band gap (HSE06) [eV]	2.43
Valence band maximum wrt. vacuum level (HSE06)	-6.24 eV
Conduction band minimum wrt. vacuum level (HSE06)	-3.87 eV

Electronic band structure (G₀W₀@PBE)

Property	Value
Band gap (G₀W₀) [eV]	3.33
Direct band gap (G₀W₀) [eV]	3.40
Valence band maximum wrt. vacuum level (G₀W₀)	-6.86 eV
Conduction band minimum wrt. vacuum level (G₀W₀)	-3.53 eV

Born charges

ZGaij	ux	uy	uz
Px	2.38	0.00	0.00
Py	0.00	2.38	-0.00
Pz	-0.00	0.00	0.23

ZSeij	ux	uy	uz
Px	-2.38	-0.00	-0.00
Py	-0.00	-2.38	0.00
Pz	0.00	-0.00	-0.23

ZSeij	ux	uy	uz
Px	-2.38	-0.00	-0.00
Py	-0.00	-2.38	0.00
Pz	0.00	-0.00	-0.23

ZGaij	ux	uy	uz
Px	2.38	0.00	0.00
Py	0.00	2.38	-0.00
Pz	-0.00	0.00	0.23

Optical polarizability

Properties
Static interband polarizability at (x) [Å]	4.184
Static interband polarizability at (y) [Å]	4.168
Static interband polarizability at (z) [Å]	0.525
Plasma frequency (x) [Å0.5]	0.000
Plasma frequency (y) [Å0.5]	0.000

Infrared polarizability

Static polarizability	[Å]
Phonons only (x)	2.29
Phonons only (y)	2.29
Phonons only (z)	0.02
Total (phonons + electrons) (x)	6.47
Total (phonons + electrons) (y)	6.46
Total (phonons + electrons) (z)	0.54

Bader charges

#	Chemical symbol	Charges [|e|]
0	Ga	0.66
1	Se	-0.68
2	Se	-0.68
3	Ga	0.70

Miscellaneous

Miscellaneous details
Unique ID	2GaSe-2
Number of atoms	4
Number of species	2
Formula	Ga2Se2
Reduced formula	GaSe
Stoichiometry	AB
Unit cell area [Å2]	12.738
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB/GaSe/Ga2Se2-8a6a5075fdf0
Old uid	Ga2Se2-8a6a5075fdf0
Inversion symmetry	Yes
Layer group	p-3m1
Layer group number	72
Structure origin	original03-18
Band gap [eV]	1.644
gap_dir	1.713
gap_dir_nosoc	1.756
Vacuum level [eV]	3.604
Fermi level [eV]	-1.350
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	2.371
gap_dir_hse	2.435
vbm_hse	-2.639

Miscellaneous details
cbm_hse	-0.268
Band gap (G₀W₀) [eV]	3.331
gap_dir_gw	3.400
vbm_gw	-3.260
cbm_gw	0.071
Static interband polarizability at (x) [Å]	4.184
Static interband polarizability at (y) [Å]	4.168
Static interband polarizability at (z) [Å]	0.525
Static polarizability (phonons) (x) [Å]	2.290
Static polarizability (phonons + electrons) (x) [Å]	6.474
Static polarizability (phonons) (y) [Å]	2.288
Static polarizability (phonons + electrons) (y) [Å]	6.456
Static polarizability (phonons) (z) [Å]	0.015
Static polarizability (phonons + electrons) (z) [Å]	0.540
Plasma frequency (x) [Å0.5]	0.000
Plasma frequency (y) [Å0.5]	0.000
Energy [eV]	-15.163
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]	0.004
Heat of formation [eV/atom]	-0.598