Overview: Te₂Ge

Structure info
Layer group	p-6m2
Layer group number	78
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.261
Heat of formation [eV/atom]	0.198
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	3.606	-0.000	0.000	Yes
2	-1.803	3.123	0.000	Yes
3	-0.000	0.000	19.177	No

Lengths [Å]	3.606	3.606	19.177
Angles [°]	90.000	90.000	120.000

Crystal structure

Symmetries
2D Bravais type	Hexagonal (hp)
Layer group number	78
Layer group	p-6m2
Space group number (bulk in AA-stacking)	187
Space group (bulk in AA-stacking)	P-6m2
Point group	-6m2
Inversion symmetry	No

Structure data
Formula	Te2Ge
Stoichiometry	AB2
Number of atoms	3
Unit cell area [Å2]	11.264
Thickness [Å]	4.071

Stability

Convex hull

GeTe2 (1GeTe2-3)
Heat of formation [eV/atom]	0.20
Energy above convex hull [eV/atom]	0.26

Monolayers from C2DB
Te2Ge2 (2GeTe-1)	-0.04 eV/atom
TeGe (1GeTe-1)	-0.01 eV/atom
Te2Ge2 (2GeTe-2)	-0.00 eV/atom
Te2Ge (1GeTe2-1)	0.07 eV/atom
Te2Ge (1GeTe2-2)	0.08 eV/atom
Te4Ge2 (2GeTe2-1)	0.14 eV/atom
Te2 (2Te-1)	0.16 eV/atom
Te2Ge, (1GeTe2-3)	0.20 eV/atom
Te4Ge2 (2GeTe2-2)	0.27 eV/atom
Te2 (2Te-2)	0.29 eV/atom
Te2Ge2 (2GeTe-3)	0.38 eV/atom
Ge2 (2Ge-1)	0.48 eV/atom
Ge2 (2Ge-2)	0.49 eV/atom

Bulk crystals from OQMD123
TeGe	-0.09 eV/atom
Ge2	0.00 eV/atom
Te3	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-0.24

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	49.89	34.87	-0.27
yy	34.88	49.67	-0.22
xy	0.00	0.00	14.05

Stiffness tensor eigenvalues
Eigenvalue 0	14.05 N/m
Eigenvalue 1	14.90 N/m
Eigenvalue 2	84.66 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)	-4.861

Fermi surface

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Ge	0.33
1	Te	-0.17
2	Te	-0.17

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	13.315
Interband polarizability (y) [Å]	13.315
Interband polarizability (z) [Å]	0.528
Plasma frequency (x) [eV Å0.5]	14.203
Plasma frequency (y) [eV Å0.5]	14.203

Raman spectrum

Mode	Frequency (1/cm)	Degeneracy
Mode 1	0.1	3
Mode 2	61.1	2
Mode 3	106.	4

Miscellaneous

Miscellaneous details
Unique ID	1GeTe2-3
Number of atoms	3
Number of species	2
Formula	Te2Ge
Reduced formula	Te2Ge
Stoichiometry	AB2
Unit cell area [Å2]	11.264
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB2/GeTe2/GeTe2-f22718f3be0b
Old uid	GeTe2-f22718f3be0b
Space group (bulk in AA-stacking)	P-6m2
Space group number (bulk in AA-stacking)	187
Point group	-6m2
Inversion symmetry	No
Layer group number	78
Layer group	p-6m2
2D Bravais type	Hexagonal (hp)
Thickness [Å]	4.071
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]	4.290
Fermi level wrt. vacuum (PBE) [eV]	-4.861
minhessianeig	-0.242
Dynamically stable	No
Interband polarizability (x) [Å]	13.315
Interband polarizability (y) [Å]	13.315
Interband polarizability (z) [Å]	0.528
Plasma frequency (x) [eV Å0.5]	14.203
Plasma frequency (y) [eV Å0.5]	14.203
Energy [eV]	-10.330
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]	0.261
Heat of formation [eV/atom]	0.198