Atoms: F₂Si₂

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

Stability
Energy above convex hull [eV/atom]	0.181
Heat of formation [eV/atom]	-1.767
Dynamically stable	Yes

Basic properties
Magnetic state	NM
Band gap [eV]	0.666
Band gap (HSE06) [eV]	1.492
Band gap (G₀W₀) [eV]	2.333

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	3.944	0.000	0.000	Yes
2	-1.972	3.416	0.000	Yes
3	0.000	0.000	17.768	No

Lengths [Å]	3.944	3.944	17.768
Angles [°]	90.000	90.000	120.000

Convex hull

F2Si2 (2FSi-1)
Heat of formation [eV/atom]	-1.77
Energy above convex hull [eV/atom]	0.18

Monolayers from C2DB
F2Si2, (2FSi-1)	-1.77 eV/atom
SiF2, (1SiF2-1)	-1.75 eV/atom
SiF2, (1SiF2-2)	-1.69 eV/atom
SiF2, (1SiF2-3)	-1.45 eV/atom
Si2, (2Si-1)	0.64 eV/atom

Bulk crystals from OQMD123
F4Si	-3.12 eV/atom
F4	0.00 eV/atom
Si2	0.00 eV/atom

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	53.80	12.38	0.03
yy	12.38	53.80	0.03
xy	-0.00	-0.00	42.43

Stiffness tensor eigenvalues
Eigenvalue 0	41.42 N/m
Eigenvalue 1	42.43 N/m
Eigenvalue 2	66.18 N/m

Phonons

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

Deformation potentials

DVB (eV)	xx	yy	xy
Γ	-1.13	-1.05	0.02
M	3.60	-1.61	4.50
K	3.84	3.85	0.02
kVBM	-1.13	-1.05	0.02

	xx	yy	xy
Band Gap	2.54	2.47	-0.00

DCB (eV)	xx	yy	xy
Γ	1.41	1.41	0.02
M	2.24	-4.06	5.41
K	0.83	0.84	0.02
kCBM	1.41	1.41	0.02

Band structure and DOS

Effective masses

Property (VBM)	Value
Min eff. mass	0.22 m0
Max eff. mass	0.22 m0
DOS eff. mass	0.22 m0
Crystal coordinates	[0.000, -0.000]
Warping parameter	-0.000
Barrier height	> 87.4 meV
Distance to barrier	> 0.0183 Å-1

Property (CBM)	Value
Min eff. mass	0.24 m0
Max eff. mass	0.24 m0
DOS eff. mass	0.24 m0
Crystal coordinates	[0.000, -0.000]
Warping parameter	0.000
Barrier height	> 186.8 meV
Distance to barrier	> 0.0183 Å-1

Electronic band structure (HSE06@PBE)

Property	Value
KVP: Band gap (HSE06) [eV]	1.49
KVP: Direct band gap (HSE06) [eV]	1.49
Valence band maximum wrt. vacuum level (HSE06)	-6.99 eV
Conduction band minimum wrt. vacuum level (HSE06)	-5.50 eV

Electronic band structure (G₀W₀@PBE)

Property	Value
Band gap (G₀W₀) [eV]	2.33
Direct band gap (G₀W₀) [eV]	2.33
Valence band maximum wrt. vacuum level (G₀W₀)	-7.63 eV
Conduction band minimum wrt. vacuum level (G₀W₀)	-5.30 eV

Born charges

ZSiij	ux	uy	uz
Px	0.26	-0.00	-0.00
Py	-0.00	0.26	0.00
Pz	0.00	0.00	0.71

ZFij	ux	uy	uz
Px	-0.26	0.00	0.00
Py	0.00	-0.26	-0.00
Pz	-0.00	-0.00	-0.71

ZSiij	ux	uy	uz
Px	0.26	-0.00	-0.00
Py	-0.00	0.26	0.00
Pz	0.00	0.00	0.71

ZFij	ux	uy	uz
Px	-0.26	0.00	0.00
Py	0.00	-0.26	-0.00
Pz	-0.00	-0.00	-0.71

Optical polarizability

Properties
Static interband polarizability at (x) [Å]	3.205
Static interband polarizability at (y) [Å]	3.205
Static interband polarizability at (z) [Å]	0.251
Plasma frequency (x) [Å0.5]	0.000
Plasma frequency (y) [Å0.5]	0.000

Infrared polarizability

Static polarizability	[Å]
Phonons only (x)	0.26
Phonons only (y)	0.26
Phonons only (z)	0.04
Total (phonons + electrons) (x)	3.46
Total (phonons + electrons) (y)	3.47
Total (phonons + electrons) (z)	0.29

Optical absorption (BSE and RPA)

Property	Value
The exciton binding energy from the Bethe–Salpeter equation (BSE) [eV].	0.73

Bader charges

#	Chemical symbol	Charges [|e|]
0	Si	0.78
1	Si	0.87
2	F	-0.82
3	F	-0.82

Miscellaneous

Miscellaneous details
Unique ID	2FSi-1
Number of atoms	4
Number of species	2
Formula	F2Si2
Reduced formula	FSi
Stoichiometry	AB
Unit cell area [Å2]	13.473
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB/FSi/F2Si2-aa042bf2fe06
Old uid	F2Si2-aa042bf2fe06
Inversion symmetry	Yes
Layer group	p-3m1
Layer group number	72
Structure origin	original03-18
Band gap [eV]	0.666
gap_dir	0.666
gap_dir_nosoc	0.683
Vacuum level [eV]	2.663
Fermi level [eV]	-3.515
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	1.492
gap_dir_hse	1.492
vbm_hse	-4.330
cbm_hse	-2.839

Miscellaneous details
Band gap (G₀W₀) [eV]	2.333
gap_dir_gw	2.333
vbm_gw	-4.971
cbm_gw	-2.638
E_B	0.727
Static interband polarizability at (x) [Å]	3.205
Static interband polarizability at (y) [Å]	3.205
Static interband polarizability at (z) [Å]	0.251
Static polarizability (phonons) (x) [Å]	0.260
Static polarizability (phonons + electrons) (x) [Å]	3.465
Static polarizability (phonons) (y) [Å]	0.261
Static polarizability (phonons + electrons) (y) [Å]	3.465
Static polarizability (phonons) (z) [Å]	0.036
Static polarizability (phonons + electrons) (z) [Å]	0.287
Plasma frequency (x) [Å0.5]	0.000
Plasma frequency (y) [Å0.5]	0.000
Energy [eV]	-21.041
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]	0.181
Heat of formation [eV/atom]	-1.767