Overview: I₂Zr₂

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

Stability
Energy above convex hull [eV/atom]	0.290
Heat of formation [eV/atom]	-0.394
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	4.171	-0.000	0.000	Yes
2	0.000	4.171	0.000	Yes
3	-0.000	0.000	19.441	No

Lengths [Å]	4.171	4.171	19.441
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	Zr2I2
Stoichiometry	AB
Number of atoms	4
Unit cell area [Å2]	17.401
Thickness [Å]	4.358

Stability

Convex hull

I2Zr2 (2IZr-2)
Heat of formation [eV/atom]	-0.39
Energy above convex hull [eV/atom]	0.29

Monolayers from C2DB
Zr2I4 (2ZrI2-1)	-0.91 eV/atom
Zr2I6 (2ZrI3-1)	-0.90 eV/atom
ZrI2 (1ZrI2-1)	-0.88 eV/atom
Zr2I6 (2ZrI3-2)	-0.86 eV/atom
ZrI2 (1ZrI2-2)	-0.77 eV/atom
I2Zr2 (2IZr-1)	-0.54 eV/atom
ZrI2 (1ZrI2-3)	-0.42 eV/atom
I2Zr2, (2IZr-2)	-0.39 eV/atom
I2Zr2 (2IZr-3)	-0.09 eV/atom

Bulk crystals from OQMD123
I12Zr4	-0.99 eV/atom
I16Zr4	-0.93 eV/atom
I8Zr4	-0.91 eV/atom
I4	0.00 eV/atom
Zr2	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-0.00

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	45.19	47.74	0.00
yy	47.74	45.19	0.00
xy	-0.00	-0.00	28.04

Stiffness tensor eigenvalues
Eigenvalue 0	-2.55 N/m
Eigenvalue 1	28.04 N/m
Eigenvalue 2	92.92 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)	-3.575

Fermi surface

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	I	-0.62
1	I	-0.62
2	Zr	0.62
3	Zr	0.62

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	10.895
Interband polarizability (y) [Å]	10.895
Interband polarizability (z) [Å]	0.465
Plasma frequency (x) [eV Å0.5]	6.897
Plasma frequency (y) [eV Å0.5]	6.897

Raman spectrum

Mode	Frequency (1/cm)	Degeneracy
Mode 1	0.1	3
Mode 2	78.2	2
Mode 3	118.4	2
Mode 4	121.9	1
Mode 5	177.3	1
Mode 6	193.5	1
Mode 7	264.5	2

Miscellaneous

Miscellaneous details
Unique ID	2IZr-2
Number of atoms	4
Number of species	2
Formula	Zr2I2
Reduced formula	ZrI
Stoichiometry	AB
Unit cell area [Å2]	17.401
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB/IZr/I2Zr2-b7a9ed5caed5
Old uid	I2Zr2-b7a9ed5caed5
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]	4.358
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]	3.840
Fermi level wrt. vacuum (PBE) [eV]	-3.575
minhessianeig	-0.000
Dynamically stable	No
Interband polarizability (x) [Å]	10.895
Interband polarizability (y) [Å]	10.895
Interband polarizability (z) [Å]	0.465
Plasma frequency (x) [eV Å0.5]	6.897
Plasma frequency (y) [eV Å0.5]	6.897
Energy [eV]	-19.337
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]	0.290
Heat of formation [eV/atom]	-0.394