Overview: Cu₄I₄

Structure info
Layer group	pbma
Layer group number	45
Structure origin	Wang23

Stability
Energy above convex hull [eV/atom]	0.031
Heat of formation [eV/atom]	-0.135
Dynamically stable	Yes

Basic properties
Magnetic	No
Band gap (PBE) [eV]	1.566
Band gap (HSE06) [eV]	3.210

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	7.303	0.000	0.000	Yes
2	0.000	4.422	0.000	Yes
3	0.000	-0.000	18.423	No

Lengths [Å]	7.303	4.422	18.423
Angles [°]	90.000	90.000	90.000

Crystal structure

Symmetries
2D Bravais type	Rectangular (op)
Layer group number	45
Layer group	pbma
Space group number (bulk in AA-stacking)	57
Space group (bulk in AA-stacking)	Pbcm
Point group	mmm
Inversion symmetry	Yes

Structure data
Formula	I4Cu4
Stoichiometry	AB
Number of atoms	8
Unit cell area [Å2]	32.292
Thickness [Å]	3.434

Stability

Convex hull

Cu4I4 (4CuI-1)
Heat of formation [eV/atom]	-0.13
Energy above convex hull [eV/atom]	0.03

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]

-0.00

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	21.98	6.52	-0.00
yy	6.84	34.06	-0.00
xy	0.00	0.00	17.46

Stiffness tensor eigenvalues
Eigenvalue 0	17.46 N/m
Eigenvalue 1	19.01 N/m
Eigenvalue 2	37.03 N/m

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	1.566
Direct band gap (PBE)	1.566
Valence band maximum wrt. vacuum (PBE)	-4.789
Conduction band minimum wrt. vacuum (PBE)	-3.223

Electronic band structure (HSE06@PBE)

Key values [eV]
Band gap (HSE06)	3.210
Direct band gap (HSE06)	3.210
Valence band maximum wrt. vacuum (HSE06)	-6.186
Conduction band minimum wrt. vacuum (HSE06)	-2.976

Electronic properties

Born charges

ZIij	ux	uy	uz
Px	-1.10	0.00	-0.08
Py	0.00	-1.21	-0.00
Pz	-0.00	-0.00	-0.22

ZIij	ux	uy	uz
Px	-1.10	0.00	-0.08
Py	-0.00	-1.21	-0.00
Pz	-0.00	-0.00	-0.22

ZCuij	ux	uy	uz
Px	1.10	0.00	-0.38
Py	-0.00	1.21	0.00
Pz	-0.05	0.00	0.22

ZCuij	ux	uy	uz
Px	1.10	0.00	-0.38
Py	0.00	1.21	0.00
Pz	-0.05	0.00	0.22

ZIij	ux	uy	uz
Px	-1.10	-0.00	0.08
Py	0.00	-1.21	-0.00
Pz	0.00	-0.00	-0.22

ZIij	ux	uy	uz
Px	-1.10	-0.00	0.08
Py	-0.00	-1.21	-0.00
Pz	0.00	-0.00	-0.22

ZCuij	ux	uy	uz
Px	1.10	-0.00	0.38
Py	-0.00	1.21	0.00
Pz	0.05	0.00	0.22

ZCuij	ux	uy	uz
Px	1.10	-0.00	0.38
Py	0.00	1.21	0.00
Pz	0.05	0.00	0.22

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	I	-0.31
1	I	-0.31
2	I	-0.31
3	I	-0.31
4	Cu	0.31
5	Cu	0.31
6	Cu	0.31
7	Cu	0.31

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	2.745
Interband polarizability (y) [Å]	2.767
Interband polarizability (z) [Å]	0.423

Infrared polarizability

Static polarizability [Å]
Phonons only (x)	1.35
Phonons only (y)	1.87
Phonons only (z)	0.05
Total (phonons + electrons) (x)	4.10
Total (phonons + electrons) (y)	4.64
Total (phonons + electrons) (z)	0.47

Miscellaneous

Miscellaneous details
Unique ID	4CuI-1
Number of atoms	8
Number of species	2
Formula	I4Cu4
Reduced formula	ICu
Stoichiometry	AB
Unit cell area [Å2]	32.292
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree_Wang23/AB/CuI/Cu4I4-2be1d5bddb63
Old uid	Cu4I4-08b631bf368c
Space group (bulk in AA-stacking)	Pbcm
Space group number (bulk in AA-stacking)	57
Point group	mmm
Inversion symmetry	Yes
Layer group number	45
Layer group	pbma
2D Bravais type	Rectangular (op)
Thickness [Å]	3.434
Structure origin	Wang23
Band gap (PBE) [eV]	1.566
Direct band gap (PBE) [eV]	1.566
gap_dir_nosoc	1.657
Vacuum level [eV]	3.392
Fermi level wrt. vacuum (PBE) [eV]	-4.006
Valence band maximum wrt. vacuum (PBE) [eV]	-4.789
Conduction band minimum wrt. vacuum (PBE) [eV]	-3.223

Miscellaneous details
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	3.210
Direct band gap (HSE06) [eV]	3.210
Fermi level wrt. vacuum (HSE) [eV]	-4.581
Valence band maximum wrt. vacuum (HSE06) [eV]	-6.186
Conduction band minimum wrt. vacuum (HSE06) [eV]	-2.976
Interband polarizability (x) [Å]	2.745
Interband polarizability (y) [Å]	2.767
Interband polarizability (z) [Å]	0.423
Static polarizability (phonons) (x) [Å]	1.354
Static polarizability (phonons + electrons) (x) [Å]	4.099
Static polarizability (phonons) (y) [Å]	1.869
Static polarizability (phonons + electrons) (y) [Å]	4.636
Static polarizability (phonons) (z) [Å]	0.047
Static polarizability (phonons + electrons) (z) [Å]	0.469
Energy [eV]	-21.698
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]	0.031
Heat of formation [eV/atom]	-0.135