Atoms: Se₂Sn₂

Structure info
Layer group	p4/mmm
Layer group number	61
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.407
Heat of formation [eV/atom]	-0.025
Dynamically stable	No

Basic properties
Magnetic state	NM
Band gap [eV]	0.084
Band gap (HSE06) [eV]	0.086

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	5.809	-0.000	0.000	Yes
2	0.000	5.809	0.000	Yes
3	0.000	0.000	15.000	No

Lengths [Å]	5.809	5.809	15.000
Angles [°]	90.000	90.000	90.000

Convex hull

Se2Sn2 (2SeSn-5)
Heat of formation [eV/atom]	-0.02
Energy above convex hull [eV/atom]	0.41

Monolayers from C2DB
Se2Sn2, (2SeSn-1)	-0.39 eV/atom
Sn9Se12, (3Sn3Se4-1)	-0.38 eV/atom
Sn8Se12, (4Sn2Se3-1)	-0.36 eV/atom
Se2Sn2, (2SeSn-2)	-0.36 eV/atom
Sn7Se12, (1Sn7Se12-1)	-0.36 eV/atom
SnSe2, (1SnSe2-1)	-0.35 eV/atom
SeSn, (1SeSn-1)	-0.33 eV/atom
SnSe2, (1SnSe2-2)	-0.29 eV/atom
Se2Sn2, (2SeSn-3)	-0.29 eV/atom
Se2Sn2, (2SeSn-4)	-0.13 eV/atom
Sn2Se6, (2SnSe3-1)	-0.12 eV/atom
Sn2Se4, (2SnSe2-1)	-0.11 eV/atom
SnSe2, (1SnSe2-3)	-0.08 eV/atom
Se2Sn2, (2SeSn-5)	-0.02 eV/atom
Se2, (2Se-1)	0.21 eV/atom
Sn4, (4Sn-1)	0.26 eV/atom
Se2, (2Se-2)	0.29 eV/atom
Sn2, (2Sn-1)	0.44 eV/atom

Bulk crystals from OQMD123
Se4Sn4	-0.43 eV/atom
Se2Sn	-0.34 eV/atom
Se3	0.00 eV/atom
Sn2	0.00 eV/atom

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	49.14	7.99	-0.00
yy	7.99	49.14	-0.00
xy	0.00	0.00	1.59

Stiffness tensor eigenvalues
Eigenvalue 0	1.59 N/m
Eigenvalue 1	41.14 N/m
Eigenvalue 2	57.13 N/m

Phonons

Property	Value
Minimum eigenvalue of Hessian [eV/Ų]	-4.67

Band structure and DOS

Effective masses

Property (VBM)	Value
Min eff. mass	0.11 m0
Max eff. mass	0.30 m0
DOS eff. mass	0.18 m0
Crystal coordinates	[0.411, 0.473]
Warping parameter	-0.012
Barrier height	6.3 meV
Distance to barrier	0.00652 Å-1

Property (CBM)	Value
Min eff. mass	0.14 m0
Max eff. mass	0.39 m0
DOS eff. mass	0.24 m0
Crystal coordinates	[0.418, 0.418]
Warping parameter	0.035
Barrier height	> 75.7 meV
Distance to barrier	> 0.0148 Å-1

Electronic band structure (HSE06@PBE)

Property	Value
KVP: Band gap (HSE06) [eV]	0.09
KVP: Direct band gap (HSE06) [eV]	0.17
Valence band maximum wrt. vacuum level (HSE06)	-3.89 eV
Conduction band minimum wrt. vacuum level (HSE06)	-3.80 eV

Optical polarizability

Properties
Static interband polarizability at (x) [Å]	8.229
Static interband polarizability at (y) [Å]	8.229
Static interband polarizability at (z) [Å]	0.223
Plasma frequency (x) [Å0.5]	3.467
Plasma frequency (y) [Å0.5]	3.467

Optical absorption (BSE and RPA)

Property	Value
The exciton binding energy from the Bethe–Salpeter equation (BSE) [eV].	0.31

Bader charges

#	Chemical symbol	Charges [|e|]
0	Sn	0.84
1	Sn	0.84
2	Se	-0.84
3	Se	-0.84

Miscellaneous

Miscellaneous details
Unique ID	2SeSn-5
Number of atoms	4
Number of species	2
Formula	Se2Sn2
Reduced formula	SeSn
Stoichiometry	AB
Unit cell area [Å2]	33.748
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB/SeSn/Se2Sn2-5236d993e815
Old uid	Se2Sn2-5236d993e815
Inversion symmetry	Yes
Layer group	p4/mmm
Layer group number	61
Structure origin	original03-18
Band gap [eV]	0.084
gap_dir	0.149
gap_dir_nosoc	0.000
Vacuum level [eV]	2.177
Fermi level [eV]	-1.808
minhessianeig	-4.668

Miscellaneous details
Dynamically stable	No
Band gap (HSE06) [eV]	0.086
gap_dir_hse	0.172
vbm_hse	-1.710
cbm_hse	-1.624
E_B	0.305
Static interband polarizability at (x) [Å]	8.229
Static interband polarizability at (y) [Å]	8.229
Static interband polarizability at (z) [Å]	0.223
Plasma frequency (x) [Å0.5]	3.467
Plasma frequency (y) [Å0.5]	3.467
Energy [eV]	-15.177
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]	0.407
Heat of formation [eV/atom]	-0.025