Overview: Al₂Se₃

Structure info
Layer group	p-3m1
Layer group number	72
Structure origin	Lyngby22_LDP

Stability
Energy above convex hull [eV/atom]	0.070
Heat of formation [eV/atom]	-0.786
Dynamically stable	No

Basic properties
Magnetic	No
Band gap (PBE) [eV]	0.686

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	3.697	0.000	0.000	Yes
2	-1.849	3.202	0.000	Yes
3	0.000	-0.000	36.367	No

Lengths [Å]	3.697	3.697	36.367
Angles [°]	90.000	90.000	120.001

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	Se3Al2
Stoichiometry	A2B3
Number of atoms	5
Unit cell area [Å2]	11.837
Thickness [Å]	6.026

Stability

Convex hull

Al2Se3 (1Al2Se3-1)
Heat of formation [eV/atom]	-0.79
Energy above convex hull [eV/atom]	0.07

Monolayers from C2DB
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
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
Al2Se5 (1Al2Se5-1)	-0.60 eV/atom
Al2Se4 (2AlSe2-1)	-0.55 eV/atom
AlSe2 (1AlSe2-1)	-0.55 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
Se2 (2Se-1)	0.21 eV/atom
Se2 (2Se-2)	0.29 eV/atom

Bulk crystals from OQMD123
Al4Se6	-0.84 eV/atom
Al	0.00 eV/atom
Se3	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-2.31

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	117.89	29.74	0.15
yy	29.38	118.25	0.12
xy	-0.00	-0.00	82.47

Stiffness tensor eigenvalues
Eigenvalue 0	82.47 N/m
Eigenvalue 1	88.50 N/m
Eigenvalue 2	147.63 N/m

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	0.686
Direct band gap (PBE)	1.179
Valence band maximum wrt. vacuum (PBE)	-6.100
Conduction band minimum wrt. vacuum (PBE)	-5.414

Effective masses

Property (VBM)	Value
Min eff. mass	0.39 m0
Max eff. mass	0.39 m0
DOS eff. mass	0.39 m0
Crystal coordinates	[-0.000, 0.000]
Warping parameter	-0.000
Barrier height	47.6 meV
Distance to barrier	0.0156 Å-1

Property (CBM)	Value
Min eff. mass	0.14 m0
Max eff. mass	0.60 m0
DOS eff. mass	0.29 m0
Crystal coordinates	[0.500, 0.000]
Warping parameter	0.004
Barrier height	> 94.2 meV
Distance to barrier	> 0.0195 Å-1

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Al	2.04
1	Se	-1.34
2	Al	2.04
3	Se	-1.41
4	Se	-1.34

Miscellaneous

Miscellaneous details
Unique ID	1Al2Se3-1
Number of atoms	5
Number of species	2
Formula	Se3Al2
Reduced formula	Se3Al2
Stoichiometry	A2B3
Unit cell area [Å2]	11.837
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree_LDP/A2B3/Al2Se3/Al2Se3-027653f98aa1
Old uid	Al2Se3-7168020ae310
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]	6.026
Structure origin	Lyngby22_LDP

Miscellaneous details
Band gap (PBE) [eV]	0.686
Direct band gap (PBE) [eV]	1.179
gap_dir_nosoc	1.292
Vacuum level [eV]	2.793
Fermi level wrt. vacuum (PBE) [eV]	-5.757
Valence band maximum wrt. vacuum (PBE) [eV]	-6.100
Conduction band minimum wrt. vacuum (PBE) [eV]	-5.414
minhessianeig	-2.309
Dynamically stable	No
Energy [eV]	-21.856
Magnetic	No
Total magnetic moment [μB]	0.000
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]	0.070
Heat of formation [eV/atom]	-0.786