Atoms: Ge₂H₂

Structure info
Layer group	p-3m1
Layer group number	72
Structure origin	original03-18
Mono/few-layer report(s)	10.1021/nn4009406

Stability
Energy above convex hull [eV/atom]	0.082
Heat of formation [eV/atom]	0.082
Dynamically stable	Yes

Basic properties
Magnetic state	NM
Band gap [eV]	0.920
Band gap (HSE06) [eV]	1.488
Band gap (G₀W₀) [eV]	2.353

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	4.077	-0.000	0.000	Yes
2	-2.038	3.530	0.000	Yes
3	0.000	0.000	17.626	No

Lengths [Å]	4.077	4.077	17.626
Angles [°]	90.000	90.000	120.000

Convex hull

Ge2H2 (2GeH-1)
Heat of formation [eV/atom]	0.08
Energy above convex hull [eV/atom]	0.08

Monolayers from C2DB
Ge2H2, (2GeH-1)	0.08 eV/atom
Ge2, (2Ge-1)	0.48 eV/atom
GeH2, (1GeH2-1)	0.49 eV/atom
Ge2, (2Ge-2)	0.49 eV/atom

Bulk crystals from OQMD123
Ge2	0.00 eV/atom
H2	0.00 eV/atom

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	47.35	10.55	0.01
yy	10.63	47.29	0.01
xy	0.00	0.00	37.65

Stiffness tensor eigenvalues
Eigenvalue 0	36.73 N/m
Eigenvalue 1	37.65 N/m
Eigenvalue 2	57.92 N/m

Phonons

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

Deformation potentials

DVB (eV)	xx	yy	xy
Γ	-4.31	-4.36	0.05
M	1.39	-4.69	5.18
K	0.97	0.94	0.03
kVBM	-4.31	-4.36	0.05

	xx	yy	xy
Band Gap	-7.43	-7.48	-0.00

DCB (eV)	xx	yy	xy
Γ	-11.73	-11.83	0.05
M	-0.72	-9.18	7.26
K	1.03	1.02	0.03
kCBM	-11.73	-11.83	0.05

Band structure and DOS

Effective masses

Property (VBM)	Value
Min eff. mass	0.10 m0
Max eff. mass	0.10 m0
DOS eff. mass	0.10 m0
Crystal coordinates	[0.000, -0.000]
Warping parameter	-0.000
Barrier height	> 175.6 meV
Distance to barrier	> 0.0177 Å-1

Property (CBM)	Value
Min eff. mass	0.07 m0
Max eff. mass	0.07 m0
DOS eff. mass	0.07 m0
Crystal coordinates	[-0.000, 0.000]
Warping parameter	0.000
Barrier height	> 562.9 meV
Distance to barrier	> 0.0177 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)	-5.22 eV
Conduction band minimum wrt. vacuum level (HSE06)	-3.73 eV

Electronic band structure (G₀W₀@PBE)

Property	Value
Band gap (G₀W₀) [eV]	2.35
Direct band gap (G₀W₀) [eV]	2.35
Valence band maximum wrt. vacuum level (G₀W₀)	-5.73 eV
Conduction band minimum wrt. vacuum level (G₀W₀)	-3.38 eV

Born charges

ZGeij	ux	uy	uz
Px	0.52	-0.00	-0.00
Py	-0.00	0.52	0.00
Pz	0.00	0.00	0.21

ZHij	ux	uy	uz
Px	-0.52	0.00	0.00
Py	0.00	-0.52	-0.00
Pz	-0.00	-0.00	-0.21

ZGeij	ux	uy	uz
Px	0.52	-0.00	-0.00
Py	-0.00	0.52	0.00
Pz	-0.00	-0.00	0.21

ZHij	ux	uy	uz
Px	-0.52	0.00	0.00
Py	0.00	-0.52	-0.00
Pz	-0.00	-0.00	-0.21

Optical polarizability

Properties
Static interband polarizability at (x) [Å]	2.829
Static interband polarizability at (y) [Å]	2.829
Static interband polarizability at (z) [Å]	0.283
Plasma frequency (x) [Å0.5]	0.000
Plasma frequency (y) [Å0.5]	0.000

Infrared polarizability

Static polarizability	[Å]
Phonons only (x)	0.71
Phonons only (y)	0.71
Phonons only (z)	0.01
Total (phonons + electrons) (x)	3.54
Total (phonons + electrons) (y)	3.54
Total (phonons + electrons) (z)	0.29

Optical absorption (BSE and RPA)

Property	Value
The exciton binding energy from the Bethe–Salpeter equation (BSE) [eV].	0.39

Bader charges

#	Chemical symbol	Charges [|e|]
0	Ge	0.30
1	Ge	0.32
2	H	-0.31
3	H	-0.31

Miscellaneous

Miscellaneous details
Unique ID	2GeH-1
Number of atoms	4
Number of species	2
Formula	Ge2H2
Reduced formula	GeH
Stoichiometry	AB
Unit cell area [Å2]	14.392
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB/GeH/Ge2H2-c6017e131897
Old uid	Ge2H2-c6017e131897
Inversion symmetry	Yes
Layer group	p-3m1
Layer group number	72
Structure origin	original03-18
Band gap [eV]	0.920
gap_dir	0.920
gap_dir_nosoc	1.018
Vacuum level [eV]	1.965
Fermi level [eV]	-2.450
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	1.488
gap_dir_hse	1.488
vbm_hse	-3.254
cbm_hse	-1.765

Miscellaneous details
Band gap (G₀W₀) [eV]	2.353
gap_dir_gw	2.353
vbm_gw	-3.768
cbm_gw	-1.415
E_B	0.385
Static interband polarizability at (x) [Å]	2.829
Static interband polarizability at (y) [Å]	2.829
Static interband polarizability at (z) [Å]	0.283
Static polarizability (phonons) (x) [Å]	0.713
Static polarizability (phonons + electrons) (x) [Å]	3.542
Static polarizability (phonons) (y) [Å]	0.714
Static polarizability (phonons + electrons) (y) [Å]	3.543
Static polarizability (phonons) (z) [Å]	0.006
Static polarizability (phonons + electrons) (z) [Å]	0.289
Plasma frequency (x) [Å0.5]	0.000
Plasma frequency (y) [Å0.5]	0.000
Energy [eV]	-15.351
Mono/few-layer report(s)	10.1021/nn4009406
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]	0.082
Heat of formation [eV/atom]	0.082