Overview: Al₆Se₉

Structure info
Layer group	p1
Layer group number	1
Structure origin	Wang23

Stability
Energy above convex hull [eV/atom]	0.083
Heat of formation [eV/atom]	-0.774
Dynamically stable	Yes

Basic properties
Magnetic	No
Band gap (PBE) [eV]	2.475
Band gap (HSE06) [eV]	3.386

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	10.415	-0.185	0.000	Yes
2	-2.730	7.253	0.000	Yes
3	-0.000	0.000	18.560	No

Lengths [Å]	10.417	7.750	18.560
Angles [°]	90.000	90.000	111.648

Crystal structure

Symmetries
2D Bravais type	Oblique (mp)
Layer group number	1
Layer group	p1
Space group number (bulk in AA-stacking)	1
Space group (bulk in AA-stacking)	P1
Point group	1
Inversion symmetry	No

Structure data
Formula	Al6Se9
Stoichiometry	A2B3
Number of atoms	15
Unit cell area [Å2]	75.038
Thickness [Å]	3.560

Stability

Convex hull

Al6Se9 (3Al2Se3-1)
Heat of formation [eV/atom]	-0.77
Energy above convex hull [eV/atom]	0.08

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	29.19	6.03	-0.84
yy	4.33	29.14	-0.70
xy	-2.21	-0.46	17.85

Stiffness tensor eigenvalues
Eigenvalue 0	17.72 N/m
Eigenvalue 1	24.06 N/m
Eigenvalue 2	34.40 N/m

Piezoelectric tensor

cij [e/Å]	xx	yy	xy
x	-0.03	0.00	-0.03
y	-0.02	-0.01	0.04
z	0.01	0.00	-0.00

cijclamped [e/Å]	xx	yy	xy
x	0.01	-0.01	-0.00
y	-0.00	0.00	0.00
z	-0.00	-0.00	-0.00

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	2.475
Direct band gap (PBE)	2.492
Valence band maximum wrt. vacuum (PBE)	-6.004
Conduction band minimum wrt. vacuum (PBE)	-3.529

Electronic band structure (HSE06@PBE)

Key values [eV]
Band gap (HSE06)	3.386
Direct band gap (HSE06)	3.386
Valence band maximum wrt. vacuum (HSE06)	-6.599
Conduction band minimum wrt. vacuum (HSE06)	-3.213

Electronic properties

Born charges

ZAlij	ux	uy	uz
Px	2.47	0.53	0.72
Py	0.08	3.13	0.13
Pz	0.14	0.06	0.40

ZAlij	ux	uy	uz
Px	3.49	-0.12	-0.62
Py	-0.08	2.67	-0.25
Pz	-0.06	-0.03	0.36

ZAlij	ux	uy	uz
Px	2.87	0.09	-0.73
Py	0.42	2.68	-0.17
Pz	-0.10	-0.03	0.36

ZSeij	ux	uy	uz
Px	-3.12	-0.32	-0.48
Py	-0.24	-1.42	-0.07
Pz	-0.12	-0.03	-0.19

ZSeij	ux	uy	uz
Px	-1.50	-0.18	0.11
Py	-0.41	-2.13	-0.12
Pz	0.02	-0.02	-0.17

ZSeij	ux	uy	uz
Px	-1.60	0.20	0.49
Py	0.24	-2.13	0.15
Pz	0.07	0.02	-0.28

ZSeij	ux	uy	uz
Px	-1.73	-0.14	-0.31
Py	-0.09	-1.49	0.02
Pz	-0.03	0.02	-0.37

ZSeij	ux	uy	uz
Px	-1.75	0.26	0.48
Py	0.37	-2.06	0.19
Pz	0.08	0.03	-0.28

ZAlij	ux	uy	uz
Px	2.43	-0.04	-0.86
Py	0.24	2.75	-0.24
Pz	-0.14	-0.04	0.36

ZAlij	ux	uy	uz
Px	2.18	0.19	0.63
Py	-0.03	2.97	0.46
Pz	0.07	0.08	0.41

ZAlij	ux	uy	uz
Px	3.63	0.05	-0.17
Py	0.14	2.46	-0.22
Pz	-0.10	-0.07	0.50

ZSeij	ux	uy	uz
Px	-1.89	-0.24	-0.12
Py	-0.23	-1.22	-0.08
Pz	0.01	-0.01	-0.35

ZSeij	ux	uy	uz
Px	-2.03	0.23	0.36
Py	0.22	-2.22	0.19
Pz	0.07	0.02	-0.30

ZSeij	ux	uy	uz
Px	-1.79	-0.64	0.02
Py	-0.73	-1.89	-0.13
Pz	-0.01	-0.03	-0.19

ZSeij	ux	uy	uz
Px	-1.65	0.15	0.46
Py	0.08	-2.11	0.15
Pz	0.07	0.03	-0.29

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Al	2.06
1	Al	2.10
2	Al	2.09
3	Al	2.07
4	Al	2.08
5	Al	2.03
6	Se	-1.44
7	Se	-1.35
8	Se	-1.36
9	Se	-1.37
10	Se	-1.41
11	Se	-1.35
12	Se	-1.37
13	Se	-1.41
14	Se	-1.39

Miscellaneous

Miscellaneous details
Unique ID	3Al2Se3-1
Number of atoms	15
Number of species	2
Formula	Al6Se9
Reduced formula	Al2Se3
Stoichiometry	A2B3
Unit cell area [Å2]	75.038
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree_Wang23/A2B3/Al2Se3/Al6Se9-c1c3b480aee7
Old uid	Al6Se9-f987fe668e33
Space group (bulk in AA-stacking)	P1
Space group number (bulk in AA-stacking)	1
Point group	1
Inversion symmetry	No
Layer group number	1
Layer group	p1
2D Bravais type	Oblique (mp)
Thickness [Å]	3.560
Structure origin	Wang23
Band gap (PBE) [eV]	2.475
Direct band gap (PBE) [eV]	2.492

Miscellaneous details
gap_dir_nosoc	2.514
Vacuum level [eV]	2.553
Fermi level wrt. vacuum (PBE) [eV]	-4.767
Valence band maximum wrt. vacuum (PBE) [eV]	-6.004
Conduction band minimum wrt. vacuum (PBE) [eV]	-3.529
minhessianeig	-0.002
Dynamically stable	Yes
Band gap (HSE06) [eV]	3.386
Direct band gap (HSE06) [eV]	3.386
Fermi level wrt. vacuum (HSE) [eV]	-4.906
Valence band maximum wrt. vacuum (HSE06) [eV]	-6.599
Conduction band minimum wrt. vacuum (HSE06) [eV]	-3.213
Energy [eV]	-65.380
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]	0.083
Heat of formation [eV/atom]	-0.774