Overview: Cu₂S₄

Structure info
Layer group	p2_1/b11
Layer group number	17
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.110
Heat of formation [eV/atom]	-0.032
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	5.555	0.000	0.000	Yes
2	-0.000	5.690	0.000	Yes
3	-0.000	0.000	16.309	No

Lengths [Å]	5.555	5.690	16.309
Angles [°]	90.000	90.000	90.000

Crystal structure

Symmetries
2D Bravais type	Rectangular (op)
Layer group number	17
Layer group	p2_1/b11
Space group number (bulk in AA-stacking)	14
Space group (bulk in AA-stacking)	P2_1/c
Point group	2/m
Inversion symmetry	Yes

Structure data
Formula	Cu2S4
Stoichiometry	AB2
Number of atoms	6
Unit cell area [Å2]	31.604
Thickness [Å]	0.941

Stability

Convex hull

Cu2S4 (2CuS2-1)
Heat of formation [eV/atom]	-0.03
Energy above convex hull [eV/atom]	0.11

Monolayers from C2DB
S4Cu6 (2S2Cu3-1)	-0.21 eV/atom
S4Cu6 (2S2Cu3-2)	-0.21 eV/atom
S2Cu4 (2SCu2-1)	-0.16 eV/atom
S2Cu4 (2SCu2-2)	-0.13 eV/atom
S4Cu6 (2S2Cu3-3)	-0.12 eV/atom
S4Cu6 (2S2Cu3-4)	-0.11 eV/atom
S6Cu12 (6SCu2-1)	-0.10 eV/atom
Cu2S2 (2CuS-1)	-0.10 eV/atom
Cu2S2 (2CuS-2)	-0.09 eV/atom
Cu2S2 (2CuS-3)	-0.05 eV/atom
Cu2S4, (2CuS2-1)	-0.03 eV/atom
Cu2S2 (2CuS-4)	-0.00 eV/atom
Cu2S2 (2CuS-5)	0.03 eV/atom
Cu2S2 (2CuS-6)	0.04 eV/atom
SCu2 (1SCu2-1)	0.12 eV/atom
Cu4S14 (2Cu2S7-1)	0.15 eV/atom
CuS2 (1CuS2-1)	0.16 eV/atom
CuS2 (1CuS2-2)	0.22 eV/atom
Cu2S5 (1Cu2S5-1)	0.27 eV/atom
CuS2 (1CuS2-3)	0.28 eV/atom
S2 (2S-1)	0.45 eV/atom
S2 (2S-2)	0.62 eV/atom

Bulk crystals from OQMD123
Cu6S6	-0.21 eV/atom
Cu2S4	-0.12 eV/atom
Cu	0.00 eV/atom
S48	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-1.18

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	37.02	12.70	0.00
yy	12.54	47.64	0.00
xy	0.00	0.00	34.65

Stiffness tensor eigenvalues
Eigenvalue 0	28.64 N/m
Eigenvalue 1	34.65 N/m
Eigenvalue 2	56.02 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)	-4.914

Fermi surface

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Cu	0.60
1	Cu	0.60
2	S	-0.30
3	S	-0.30
4	S	-0.30
5	S	-0.30

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	12.405
Interband polarizability (y) [Å]	7.988
Interband polarizability (z) [Å]	0.219
Plasma frequency (x) [eV Å0.5]	3.073
Plasma frequency (y) [eV Å0.5]	6.117

Raman spectrum

Mode	Frequency (1/cm)	Degeneracy
Mode 1	81.2	1
Mode 2	0.3	3
Mode 3	107.7	1
Mode 4	130.9	1
Mode 5	138.5	1
Mode 6	143.7	1
Mode 7	153.9	1
Mode 8	169.5	1
Mode 9	250.1	1
Mode 10	266.7	1
Mode 11	297.3	1
Mode 12	321.8	1
Mode 13	326.9	2
Mode 14	488.6	2

Miscellaneous

Miscellaneous details
Unique ID	2CuS2-1
Number of atoms	6
Number of species	2
Formula	Cu2S4
Reduced formula	CuS2
Stoichiometry	AB2
Unit cell area [Å2]	31.604
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/AB2/CuS2/Cu2S4-05eb05644de0
Old uid	Cu2S4-05eb05644de0
Space group (bulk in AA-stacking)	P2_1/c
Space group number (bulk in AA-stacking)	14
Point group	2/m
Inversion symmetry	Yes
Layer group number	17
Layer group	p2_1/b11
2D Bravais type	Rectangular (op)
Thickness [Å]	0.941
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]	2.257
Fermi level wrt. vacuum (PBE) [eV]	-4.914
minhessianeig	-1.179
Dynamically stable	No
Interband polarizability (x) [Å]	12.405
Interband polarizability (y) [Å]	7.988
Interband polarizability (z) [Å]	0.219
Plasma frequency (x) [eV Å0.5]	3.073
Plasma frequency (y) [eV Å0.5]	6.117
Energy [eV]	-23.855
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]	0.110
Heat of formation [eV/atom]	-0.032