Overview: Cu₂I₄

Structure info
Layer group	c2/m11
Layer group number	18
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.074
Heat of formation [eV/atom]	-0.055
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	4.106	0.000	0.000	Yes
2	-0.000	6.638	0.000	Yes
3	-0.000	0.000	18.210	No

Lengths [Å]	4.106	6.638	18.210
Angles [°]	90.000	90.000	90.000

Crystal structure

Symmetries
2D Bravais type	Centered rectangular (oc)
Layer group number	18
Layer group	c2/m11
Space group number (bulk in AA-stacking)	12
Space group (bulk in AA-stacking)	C2/m
Point group	2/m
Inversion symmetry	Yes

Structure data
Formula	I4Cu2
Stoichiometry	AB2
Number of atoms	6
Unit cell area [Å2]	27.255
Thickness [Å]	3.225

Stability

Convex hull

Cu2I4 (2CuI2-2)
Heat of formation [eV/atom]	-0.06
Energy above convex hull [eV/atom]	0.07

Monolayers from C2DB
Cu2I2 (2CuI-1)	-0.17 eV/atom
Cu2I2 (2CuI-2)	-0.16 eV/atom
Cu3I3 (3CuI-1)	-0.15 eV/atom
Cu5I5 (5CuI-1)	-0.14 eV/atom
Cu6I6 (6CuI-1)	-0.14 eV/atom
Cu4I4 (4CuI-1)	-0.13 eV/atom
CuI2 (1CuI2-1)	-0.13 eV/atom
Cu2I3 (1Cu2I3-1)	-0.12 eV/atom
Cu4I6 (2Cu2I3-1)	-0.12 eV/atom
Cu3I6 (3CuI2-1)	-0.11 eV/atom
Cu9I11 (1Cu9I11-1)	-0.10 eV/atom
Cu6I6 (6CuI-2)	-0.10 eV/atom
Cu3I3 (3CuI-2)	-0.10 eV/atom
Cu6I6 (6CuI-3)	-0.10 eV/atom
Cu3I3 (3CuI-3)	-0.10 eV/atom
Cu3I3 (3CuI-4)	-0.09 eV/atom
Cu2I4 (2CuI2-1)	-0.09 eV/atom
Cu3I5 (1Cu3I5-1)	-0.09 eV/atom
Cu4I4 (4CuI-2)	-0.09 eV/atom
CuI (1CuI-1)	-0.08 eV/atom
Cu4I8 (4CuI2-1)	-0.08 eV/atom
Cu4I8 (4CuI2-2)	-0.08 eV/atom
Cu3I4 (1Cu3I4-1)	-0.07 eV/atom
Cu2I4, (2CuI2-2)	-0.06 eV/atom
Cu4I6 (2Cu2I3-2)	-0.05 eV/atom
CuI2 (1CuI2-2)	-0.05 eV/atom
Cu2I5 (1Cu2I5-1)	-0.03 eV/atom
Cu2I6 (2CuI3-1)	0.05 eV/atom
CuI2 (1CuI2-3)	0.09 eV/atom
Cu2I6 (2CuI3-2)	0.10 eV/atom

Bulk crystals from OQMD123
CuI	-0.16 eV/atom
Cu	0.00 eV/atom
I4	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-0.47

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	19.52	12.13	0.00
yy	12.29	32.42	0.00
xy	0.00	0.00	-198.08

Stiffness tensor eigenvalues
Eigenvalue 0	-198.08 N/m
Eigenvalue 1	12.16 N/m
Eigenvalue 2	39.77 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)	-5.586

Fermi surface

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Cu	0.47
1	I	-0.23
2	I	-0.23
3	Cu	0.47
4	I	-0.23
5	I	-0.23

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	30.124
Interband polarizability (y) [Å]	27.838
Interband polarizability (z) [Å]	0.427
Plasma frequency (x) [eV Å0.5]	5.270
Plasma frequency (y) [eV Å0.5]	6.744

Miscellaneous

Miscellaneous details
Unique ID	2CuI2-2
Number of atoms	6
Number of species	2
Formula	I4Cu2
Reduced formula	I2Cu
Stoichiometry	AB2
Unit cell area [Å2]	27.255
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB2/CuI2/Cu2I4-0322a16c0170
Old uid	Cu2I4-0322a16c0170
Space group (bulk in AA-stacking)	C2/m
Space group number (bulk in AA-stacking)	12
Point group	2/m
Inversion symmetry	Yes
Layer group number	18
Layer group	c2/m11
2D Bravais type	Centered rectangular (oc)
Thickness [Å]	3.225
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]	3.509
Fermi level wrt. vacuum (PBE) [eV]	-5.586
minhessianeig	-0.474
Dynamically stable	No
Interband polarizability (x) [Å]	30.124
Interband polarizability (y) [Å]	27.838
Interband polarizability (z) [Å]	0.427
Plasma frequency (x) [eV Å0.5]	5.270
Plasma frequency (y) [eV Å0.5]	6.744
Energy [eV]	-13.597
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]	0.074
Heat of formation [eV/atom]	-0.055