Overview: Al₄Se₆

Structure info
Layer group	pmmn
Layer group number	46
Structure origin	Wang23

Stability
Energy above convex hull [eV/atom]	0.024
Heat of formation [eV/atom]	-0.833
Dynamically stable	Yes

Basic properties
Magnetic	No
Band gap (PBE) [eV]	1.524
Band gap (HSE06) [eV]	2.462

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	10.634	0.000	0.000	Yes
2	-0.000	3.842	0.000	Yes
3	0.000	0.000	19.790	No

Lengths [Å]	10.634	3.842	19.790
Angles [°]	90.000	90.000	90.000

Crystal structure

Symmetries
2D Bravais type	Rectangular (op)
Layer group number	46
Layer group	pmmn
Space group number (bulk in AA-stacking)	59
Space group (bulk in AA-stacking)	Pmmn
Point group	mmm
Inversion symmetry	Yes

Structure data
Formula	Se6Al4
Stoichiometry	A2B3
Number of atoms	10
Unit cell area [Å2]	40.858
Thickness [Å]	4.790

Stability

Convex hull

Al4Se6 (2Al2Se3-2)
Heat of formation [eV/atom]	-0.83
Energy above convex hull [eV/atom]	0.02

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]

-0.00

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	22.56	5.24	-0.00
yy	3.91	50.25	-0.00
xy	0.00	0.00	9.44

Stiffness tensor eigenvalues
Eigenvalue 0	9.44 N/m
Eigenvalue 1	21.83 N/m
Eigenvalue 2	50.97 N/m

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	1.524
Direct band gap (PBE)	1.524
Valence band maximum wrt. vacuum (PBE)	-5.100
Conduction band minimum wrt. vacuum (PBE)	-3.576

Electronic band structure (HSE06@PBE)

Key values [eV]
Band gap (HSE06)	2.462
Direct band gap (HSE06)	2.462
Valence band maximum wrt. vacuum (HSE06)	-5.722
Conduction band minimum wrt. vacuum (HSE06)	-3.260

Electronic properties

Born charges

ZAlij	ux	uy	uz
Px	2.21	0.01	1.26
Py	-0.00	2.57	0.00
Pz	0.21	0.00	0.47

ZAlij	ux	uy	uz
Px	2.21	0.01	-1.26
Py	-0.00	2.57	-0.00
Pz	-0.21	-0.00	0.47

ZSeij	ux	uy	uz
Px	-1.01	0.00	0.50
Py	0.00	-2.20	-0.00
Pz	0.08	-0.00	-0.34

ZSeij	ux	uy	uz
Px	-1.01	0.00	-0.50
Py	0.00	-2.20	0.00
Pz	-0.08	0.00	-0.34

ZSeij	ux	uy	uz
Px	-2.41	0.00	0.00
Py	0.00	-0.74	-0.00
Pz	0.00	-0.00	-0.25

ZAlij	ux	uy	uz
Px	2.21	-0.01	1.26
Py	0.00	2.57	-0.00
Pz	0.21	-0.00	0.47

ZAlij	ux	uy	uz
Px	2.21	-0.01	-1.26
Py	0.00	2.57	0.00
Pz	-0.21	0.00	0.47

ZSeij	ux	uy	uz
Px	-1.01	-0.00	0.50
Py	-0.00	-2.20	0.00
Pz	0.08	0.00	-0.34

ZSeij	ux	uy	uz
Px	-1.01	-0.00	-0.50
Py	-0.00	-2.20	-0.00
Pz	-0.08	-0.00	-0.34

ZSeij	ux	uy	uz
Px	-2.41	0.00	-0.00
Py	0.00	-0.74	0.00
Pz	0.00	0.00	-0.25

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Al	2.08
1	Al	2.08
2	Al	2.08
3	Al	2.08
4	Se	-1.41
5	Se	-1.41
6	Se	-1.41
7	Se	-1.41
8	Se	-1.35
9	Se	-1.35

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	1.905
Interband polarizability (y) [Å]	2.083
Interband polarizability (z) [Å]	0.410

Infrared polarizability

Static polarizability [Å]
Phonons only (x)	0.86
Phonons only (y)	5.30
Phonons only (z)	0.03
Total (phonons + electrons) (x)	2.77
Total (phonons + electrons) (y)	7.38
Total (phonons + electrons) (z)	0.44

Miscellaneous

Miscellaneous details
Unique ID	2Al2Se3-2
Number of atoms	10
Number of species	2
Formula	Se6Al4
Reduced formula	Se3Al2
Stoichiometry	A2B3
Unit cell area [Å2]	40.858
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree_Wang23/A2B3/Al2Se3/Al4Se6-a50ca6c3c475
Old uid	Al4Se6-94e3879ea6f4
Space group (bulk in AA-stacking)	Pmmn
Space group number (bulk in AA-stacking)	59
Point group	mmm
Inversion symmetry	Yes
Layer group number	46
Layer group	pmmn
2D Bravais type	Rectangular (op)
Thickness [Å]	4.790
Structure origin	Wang23
Band gap (PBE) [eV]	1.524
Direct band gap (PBE) [eV]	1.524
gap_dir_nosoc	1.529
Vacuum level [eV]	2.929
Fermi level wrt. vacuum (PBE) [eV]	-4.338
Valence band maximum wrt. vacuum (PBE) [eV]	-5.100
Conduction band minimum wrt. vacuum (PBE) [eV]	-3.576

Miscellaneous details
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	2.462
Direct band gap (HSE06) [eV]	2.462
Fermi level wrt. vacuum (HSE) [eV]	-4.491
Valence band maximum wrt. vacuum (HSE06) [eV]	-5.722
Conduction band minimum wrt. vacuum (HSE06) [eV]	-3.260
Interband polarizability (x) [Å]	1.905
Interband polarizability (y) [Å]	2.083
Interband polarizability (z) [Å]	0.410
Static polarizability (phonons) (x) [Å]	0.860
Static polarizability (phonons + electrons) (x) [Å]	2.766
Static polarizability (phonons) (y) [Å]	5.297
Static polarizability (phonons + electrons) (y) [Å]	7.380
Static polarizability (phonons) (z) [Å]	0.027
Static polarizability (phonons + electrons) (z) [Å]	0.437
Energy [eV]	-44.175
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]	0.024
Heat of formation [eV/atom]	-0.833