Overview: Ag₂I₂

Structure info
Layer group	cmme
Layer group number	48
Structure origin	Lyngby22_LDP

Stability
Energy above convex hull [eV/atom]	0.051
Heat of formation [eV/atom]	-0.218
Dynamically stable	No

Basic properties
Magnetic	No
Band gap (PBE) [eV]	2.509

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	4.817	-0.612	0.000	Yes
2	-0.612	4.817	0.000	Yes
3	0.000	-0.000	33.814	No

Lengths [Å]	4.856	4.856	33.814
Angles [°]	90.000	90.000	104.486

Crystal structure

Symmetries
2D Bravais type	Centered rectangular (oc)
Layer group number	48
Layer group	cmme
Space group number (bulk in AA-stacking)	67
Space group (bulk in AA-stacking)	Cmme
Point group	mmm
Inversion symmetry	Yes

Structure data
Formula	Ag2I2
Stoichiometry	AB
Number of atoms	4
Unit cell area [Å2]	22.831
Thickness [Å]	3.763

Stability

Convex hull

Ag2I2 (2AgI-3)
Heat of formation [eV/atom]	-0.22
Energy above convex hull [eV/atom]	0.05

Monolayers from C2DB
Ag2I2 (2AgI-1)	-0.26 eV/atom
Ag2I2 (2AgI-2)	-0.25 eV/atom
Ag6I6 (6AgI-1)	-0.24 eV/atom
Ag5I5 (5AgI-1)	-0.24 eV/atom
Ag6I6 (6AgI-2)	-0.23 eV/atom
Ag2I2, (2AgI-3)	-0.22 eV/atom
Ag6I6 (6AgI-3)	-0.22 eV/atom
Ag6I6 (6AgI-4)	-0.21 eV/atom
Ag3I3 (3AgI-1)	-0.21 eV/atom
Ag3I3 (3AgI-2)	-0.21 eV/atom
AgI (1AgI-1)	-0.20 eV/atom
Ag2I2 (2AgI-4)	-0.19 eV/atom
Ag6I8 (2Ag3I4-1)	-0.19 eV/atom
I12Ag15 (3I4Ag5-1)	-0.17 eV/atom
Ag6I12 (6AgI2-1)	-0.16 eV/atom
Ag3I5 (1Ag3I5-1)	-0.14 eV/atom
Ag2I6 (2AgI3-1)	-0.13 eV/atom
Ag4I8 (4AgI2-1)	-0.12 eV/atom
Ag2I4 (2AgI2-1)	-0.12 eV/atom
Ag2I6 (2AgI3-2)	-0.11 eV/atom
Ag4I8 (4AgI2-2)	-0.10 eV/atom
Ag4I12 (4AgI3-1)	-0.09 eV/atom
Ag2I4 (2AgI2-2)	-0.08 eV/atom
AgI3 (1AgI3-1)	-0.07 eV/atom
AgI2 (1AgI2-1)	-0.06 eV/atom
AgI2 (1AgI2-2)	-0.06 eV/atom
AgI2 (1AgI2-3)	0.03 eV/atom
Ag2I6 (2AgI3-3)	0.07 eV/atom
Ag2I6 (2AgI3-4)	0.07 eV/atom
Ag2 (2Ag-1)	0.31 eV/atom

Bulk crystals from OQMD123
AgI	-0.27 eV/atom
Ag4	0.00 eV/atom
I4	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-0.16

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	6.59	3.68	1.76
yy	3.74	6.52	1.76
xy	1.87	1.93	7.07

Stiffness tensor eigenvalues
Eigenvalue 0	2.84 N/m
Eigenvalue 1	5.63 N/m
Eigenvalue 2	11.71 N/m

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	2.509
Direct band gap (PBE)	2.509
Valence band maximum wrt. vacuum (PBE)	-5.689
Conduction band minimum wrt. vacuum (PBE)	-3.181

Effective masses

Property (VBM)	Value
Min eff. mass	0.37 m0
Max eff. mass	0.54 m0
DOS eff. mass	0.45 m0
Crystal coordinates	[-0.000, -0.000]
Warping parameter	-0.002
Barrier height	> 47.2 meV
Distance to barrier	> 0.0134 Å-1

Property (CBM)	Value
Min eff. mass	0.59 m0
Max eff. mass	1.02 m0
DOS eff. mass	0.78 m0
Crystal coordinates	[0.000, -0.000]
Warping parameter	0.002
Barrier height	> 26.0 meV
Distance to barrier	> 0.0134 Å-1

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	I	-0.24
1	Ag	0.24
2	Ag	0.24
3	I	-0.24

Miscellaneous

Miscellaneous details
Unique ID	2AgI-3
Number of atoms	4
Number of species	2
Formula	Ag2I2
Reduced formula	AgI
Stoichiometry	AB
Unit cell area [Å2]	22.831
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree_LDP/AB/AgI/Ag2I2-b63dea680da2
Old uid	Ag2I2-e6b38b9ed7b6
Space group (bulk in AA-stacking)	Cmme
Space group number (bulk in AA-stacking)	67
Point group	mmm
Inversion symmetry	Yes
Layer group number	48
Layer group	cmme
2D Bravais type	Centered rectangular (oc)
Thickness [Å]	3.763
Structure origin	Lyngby22_LDP

Miscellaneous details
Band gap (PBE) [eV]	2.509
Direct band gap (PBE) [eV]	2.509
gap_dir_nosoc	2.582
Vacuum level [eV]	1.487
Fermi level wrt. vacuum (PBE) [eV]	-4.435
Valence band maximum wrt. vacuum (PBE) [eV]	-5.689
Conduction band minimum wrt. vacuum (PBE) [eV]	-3.181
minhessianeig	-0.163
Dynamically stable	No
Energy [eV]	-9.508
Magnetic	No
Total magnetic moment [μB]	0.000
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]	0.051
Heat of formation [eV/atom]	-0.218