Overview: Te₂Ti₂

Structure info
Layer group	p4/nmm
Layer group number	64
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.274
Heat of formation [eV/atom]	-0.433
Dynamically stable	No

Basic properties
Magnetic	No
Band gap (PBE) [eV]	0.000

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	4.271	-0.000	0.000	Yes
2	0.000	4.271	0.000	Yes
3	0.000	0.000	18.441	No

Lengths [Å]	4.271	4.271	18.441
Angles [°]	90.000	90.000	90.000

Crystal structure

Symmetries
2D Bravais type	Square (tp)
Layer group number	64
Layer group	p4/nmm
Space group number (bulk in AA-stacking)	129
Space group (bulk in AA-stacking)	P4/nmm
Point group	4/mmm
Inversion symmetry	Yes

Structure data
Formula	Te2Ti2
Stoichiometry	AB
Number of atoms	4
Unit cell area [Å2]	18.242
Thickness [Å]	3.432

Stability

Convex hull

Te2Ti2 (2TeTi-3)
Heat of formation [eV/atom]	-0.43
Energy above convex hull [eV/atom]	0.27

Monolayers from C2DB
Te12Ti7 (1Ti7Te12-1)	-0.72 eV/atom
Te2Ti (1TiTe2-1)	-0.69 eV/atom
Te12Ti8 (4Ti2Te3-1)	-0.69 eV/atom
Te3Ti2 (1Ti2Te3-1)	-0.67 eV/atom
Te12Ti9 (3Ti3Te4-1)	-0.65 eV/atom
Te2Ti (1TiTe2-2)	-0.59 eV/atom
Te6Ti2 (2TiTe3-1)	-0.49 eV/atom
Te2Ti2 (2TeTi-1)	-0.45 eV/atom
Te2Ti2 (2TeTi-2)	-0.44 eV/atom
Te2Ti2, (2TeTi-3)	-0.43 eV/atom
Te2Ti (1TiTe2-3)	-0.36 eV/atom
Te2Ti2 (2TeTi-4)	-0.10 eV/atom
Te2Ti2 (2TeTi-5)	-0.08 eV/atom
Te2 (2Te-1)	0.16 eV/atom
Te2 (2Te-2)	0.29 eV/atom

Bulk crystals from OQMD123
Te4Ti3	-0.73 eV/atom
Te2Ti	-0.70 eV/atom
Te4Ti5	-0.69 eV/atom
Te3	0.00 eV/atom
Ti3	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-1.15

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	-2.41	39.48	0.00
yy	39.48	-2.41	0.00
xy	0.00	0.00	17.91

Stiffness tensor eigenvalues
Eigenvalue 0	-41.89 N/m
Eigenvalue 1	17.91 N/m
Eigenvalue 2	37.07 N/m

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	0.000
Direct band gap (PBE)	0.000
Fermi level wrt. vacuum (PBE)	-4.183

Fermi surface

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Ti	1.04
1	Ti	1.04
2	Te	-1.04
3	Te	-1.04

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	13.081
Interband polarizability (y) [Å]	13.658
Interband polarizability (z) [Å]	0.408
Plasma frequency (x) [eV Å0.5]	6.604
Plasma frequency (y) [eV Å0.5]	6.610

Miscellaneous

Miscellaneous details
Unique ID	2TeTi-3
Number of atoms	4
Number of species	2
Formula	Te2Ti2
Reduced formula	TeTi
Stoichiometry	AB
Unit cell area [Å2]	18.242
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB/TeTi/Te2Ti2-f1e1795012a8
Old uid	Te2Ti2-f1e1795012a8
Space group (bulk in AA-stacking)	P4/nmm
Space group number (bulk in AA-stacking)	129
Point group	4/mmm
Inversion symmetry	Yes
Layer group number	64
Layer group	p4/nmm
2D Bravais type	Square (tp)
Thickness [Å]	3.432
Structure origin	original03-18
Band gap (PBE) [eV]	0.000

Miscellaneous details
Direct band gap (PBE) [eV]	0.000
gap_dir_nosoc	0.000
Vacuum level [eV]	3.350
Fermi level wrt. vacuum (PBE) [eV]	-4.183
minhessianeig	-1.146
Dynamically stable	No
Interband polarizability (x) [Å]	13.081
Interband polarizability (y) [Å]	13.658
Interband polarizability (z) [Å]	0.408
Plasma frequency (x) [eV Å0.5]	6.604
Plasma frequency (y) [eV Å0.5]	6.610
Energy [eV]	-21.521
Magnetic	No
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]	0.274
Heat of formation [eV/atom]	-0.433