Overview: As₂

Structure info
Layer group	p-3m1
Layer group number	72
Structure origin	original03-18
COD id of parent bulk structure	COD 5000219
Mono/few-layer report(s)	10.1088/2053-1583/ab64fb

Stability
Energy above convex hull [eV/atom]	0.005
Heat of formation [eV/atom]	0.005
Dynamically stable	Yes

Basic properties
Magnetic	No
Band gap [eV]	1.483
Band gap (HSE06) [eV]	2.019

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	3.608	-0.000	0.000	Yes
2	-1.804	3.124	0.000	Yes
3	0.000	0.000	15.459	No

Lengths [Å]	3.608	3.608	15.459
Angles [°]	90.000	90.000	120.000

Crystal structure

Symmetries
2D Bravais type	Hexagonal (hp)
Layer group number	72
Layer group	p-3m1
Space group number (bulk in AA-stacking)	164
Space group (bulk in AA-stacking)	P-3m1
Point group	-3m
Inversion symmetry	Yes

Structure data
Formula	As2
Stoichiometry	A
Number of atoms	2
Unit cell area [Å2]	11.271
Thickness [Å]	1.396

Stability

Convex hull

As2 (2As-1)
Heat of formation [eV/atom]	0.01
Energy above convex hull [eV/atom]	0.01

Monolayers from C2DB
As2, (2As-1)	0.01 eV/atom
As4 (4As-1)	0.04 eV/atom

Bulk crystals from OQMD123
As2	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-0.00

Linear deformations

Deformation potentials

DVB [eV]	xx	yy	xy
Γ	-6.38	-6.35	-0.00
M	1.35	2.12	-0.86
K	1.26	1.26	-0.00
kVBM	-6.38	-6.35	-0.00

	xx	yy	xy
Band gap [eV]	-0.03	9.89	0.00

DCB [eV]	xx	yy	xy
Γ	-10.63	-10.65	0.00
M	-0.26	-6.89	5.83
K	2.79	2.79	-0.00
kCBM	-6.40	3.53	-0.00

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	52.51	8.50	-0.00
yy	8.48	52.47	0.00
xy	-0.00	-0.00	43.03

Stiffness tensor eigenvalues
Eigenvalue 0	43.03 N/m
Eigenvalue 1	44.00 N/m
Eigenvalue 2	60.98 N/m

Electronic bands

Band structure and DOS

Electronic band structure (HSE06@PBE)

Details
Band gap (HSE06) [eV]	2.019
Direct band gap (HSE06) [eV]	2.451
Valence band maximum wrt. vacuum level (HSE06) [eV]	-5.556
Conduction band minimum vs. vacuum (HSE06) [eV]	-3.537

Effective masses

Property (VBM)	Value
Min eff. mass	0.16 m0
Max eff. mass	0.16 m0
DOS eff. mass	0.16 m0
Crystal coordinates	[0.000, 0.000]
Warping parameter	-0.000
Barrier height	> 210.1 meV
Distance to barrier	> 0.02 Å-1

Property (CBM)	Value
Min eff. mass	0.13 m0
Max eff. mass	0.50 m0
DOS eff. mass	0.25 m0
Crystal coordinates	[0.311, 0.000]
Warping parameter	0.010
Barrier height	> 96.5 meV
Distance to barrier	> 0.0202 Å-1

Electronic properties

Born charges

ZAsij	ux	uy	uz
Px	-0.00	0.00	0.00
Py	-0.00	-0.00	-0.00
Pz	0.00	0.00	0.00

ZAsij	ux	uy	uz
Px	-0.00	0.00	0.00
Py	-0.00	-0.00	-0.00
Pz	0.00	0.00	0.00

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	As	-0.00
1	As	0.00

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	4.331
Interband polarizability (y) [Å]	4.331
Interband polarizability (z) [Å]	0.300
Plasma frequency (x) [eV Å0.5]	0.000
Plasma frequency (y) [eV Å0.5]	0.000

Infrared polarizability

Static polarizability [Å]
Phonons only (x)	0.00
Phonons only (y)	0.00
Phonons only (z)	0.00
Total (phonons + electrons) (x)	4.33
Total (phonons + electrons) (y)	4.33
Total (phonons + electrons) (z)	0.30

Raman spectrum

Mode	Frequency (1/cm)	Degeneracy
Mode 1	0.	3
Mode 2	242.5	2
Mode 3	310.7	1

Miscellaneous

Miscellaneous details
Unique ID	2As-1
Number of atoms	2
Number of species	1
Formula	As2
Reduced formula	As
Stoichiometry	A
Unit cell area [Å2]	11.271
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/A/As/As2-2cfe371476fd
Old uid	As2-2cfe371476fd
Space group (bulk in AA-stacking)	P-3m1
Space group number (bulk in AA-stacking)	164
Point group	-3m
Inversion symmetry	Yes
Layer group number	72
Layer group	p-3m1
2D Bravais type	Hexagonal (hp)
Thickness [Å]	1.396
Structure origin	original03-18
Band gap [eV]	1.483
gap_dir	1.805
gap_dir_nosoc	1.945
Vacuum level [eV]	2.811
Fermi level [eV]	-1.689
minhessianeig	-0.000
Dynamically stable	Yes

Miscellaneous details
Band gap (HSE06) [eV]	2.019
Direct band gap (HSE06) [eV]	2.451
Valence band maximum wrt. vacuum level (HSE06) [eV]	-5.556
Conduction band minimum vs. vacuum (HSE06) [eV]	-3.537
Interband polarizability (x) [Å]	4.331
Interband polarizability (y) [Å]	4.331
Interband polarizability (z) [Å]	0.300
Static polarizability (phonons) (x) [Å]	0.000
Static polarizability (phonons + electrons) (x) [Å]	4.331
Static polarizability (phonons) (y) [Å]	0.000
Static polarizability (phonons + electrons) (y) [Å]	4.331
Static polarizability (phonons) (z) [Å]	0.000
Static polarizability (phonons + electrons) (z) [Å]	0.300
Plasma frequency (x) [eV Å0.5]	0.000
Plasma frequency (y) [eV Å0.5]	0.000
Energy [eV]	-9.316
COD id of parent bulk structure	COD 5000219
Mono/few-layer report(s)	10.1088/2053-1583/ab64fb
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]	0.005
Heat of formation [eV/atom]	0.005