Overview: S₂Ag₄

Structure info
Layer group	p4/nmm
Layer group number	64
Structure origin	Wang23

Stability
Energy above convex hull [eV/atom]	0.000
Heat of formation [eV/atom]	-0.075
Dynamically stable	Yes

Basic properties
Magnetic	No
Band gap (PBE) [eV]	1.686
Band gap (HSE06) [eV]	2.619

Repeat: 1234   Download: XYZ CIF JSON

Axis	x [Å]	y [Å]	z [Å]	Periodic
1	5.886	0.000	0.000	Yes
2	-0.000	5.886	0.000	Yes
3	0.000	0.000	17.550	No

Lengths [Å]	5.886	5.886	17.550
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	Ag4S2
Stoichiometry	AB2
Number of atoms	6
Unit cell area [Å2]	34.649
Thickness [Å]	2.490

Stability

Convex hull

S2Ag4 (2SAg2-1)
Heat of formation [eV/atom]	-0.08
Energy above convex hull [eV/atom]	0.00

Monolayers from C2DB
S2Ag4, (2SAg2-1)	-0.08 eV/atom
S4Ag8 (4SAg2-1)	-0.07 eV/atom
S2Ag4 (2SAg2-2)	-0.04 eV/atom
S4Ag8 (4SAg2-2)	0.00 eV/atom
Ag6S6 (6AgS-1)	0.03 eV/atom
Ag2S2 (2AgS-1)	0.06 eV/atom
Ag2S4 (2AgS2-1)	0.07 eV/atom
Ag4S6 (2Ag2S3-1)	0.07 eV/atom
Ag4S6 (2Ag2S3-2)	0.08 eV/atom
Ag4S6 (2Ag2S3-3)	0.08 eV/atom
Ag4S6 (2Ag2S3-4)	0.09 eV/atom
Ag2S2 (2AgS-2)	0.12 eV/atom
Ag4S16 (4AgS4-1)	0.20 eV/atom
SAg2 (1SAg2-1)	0.23 eV/atom
Ag2S2 (2AgS-3)	0.23 eV/atom
Ag2S2 (2AgS-4)	0.25 eV/atom
Ag2S2 (2AgS-5)	0.28 eV/atom
AgS2 (1AgS2-1)	0.30 eV/atom
Ag2S5 (1Ag2S5-1)	0.30 eV/atom
Ag2S2 (2AgS-6)	0.30 eV/atom
Ag2 (2Ag-1)	0.31 eV/atom
Ag2S4 (2AgS2-2)	0.37 eV/atom
AgS2 (1AgS2-2)	0.43 eV/atom
S2 (2S-1)	0.45 eV/atom
AgS2 (1AgS2-3)	0.49 eV/atom
S2 (2S-2)	0.62 eV/atom

Bulk crystals from OQMD123
Ag4S2	-0.07 eV/atom
Ag4	0.00 eV/atom
S48	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-0.00

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	22.64	4.27	0.00
yy	4.27	22.64	0.00
xy	0.00	0.00	25.56

Stiffness tensor eigenvalues
Eigenvalue 0	18.37 N/m
Eigenvalue 1	25.56 N/m
Eigenvalue 2	26.91 N/m

Electronic bands

Band structure and DOS

Key values [eV]
Band gap (PBE)	1.686
Direct band gap (PBE)	1.686
Valence band maximum wrt. vacuum (PBE)	-5.702
Conduction band minimum wrt. vacuum (PBE)	-4.016

Electronic band structure (HSE06@PBE)

Key values [eV]
Band gap (HSE06)	2.619
Direct band gap (HSE06)	2.619
Valence band maximum wrt. vacuum (HSE06)	-6.579
Conduction band minimum wrt. vacuum (HSE06)	-3.960

Electronic properties

Born charges

ZSij	ux	uy	uz
Px	-1.28	0.00	0.00
Py	-0.00	-1.28	0.00
Pz	0.00	0.00	-0.14

ZAgij	ux	uy	uz
Px	0.64	-0.38	0.33
Py	-0.38	0.64	-0.33
Pz	0.08	-0.08	0.07

ZAgij	ux	uy	uz
Px	0.64	-0.38	-0.33
Py	-0.38	0.64	0.33
Pz	-0.08	0.08	0.07

ZSij	ux	uy	uz
Px	-1.28	-0.00	0.00
Py	0.00	-1.28	-0.00
Pz	0.00	-0.00	-0.14

ZAgij	ux	uy	uz
Px	0.64	0.38	-0.33
Py	0.38	0.64	-0.33
Pz	-0.08	-0.08	0.07

ZAgij	ux	uy	uz
Px	0.64	0.38	0.33
Py	0.38	0.64	0.33
Pz	0.08	0.08	0.07

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	S	-0.53
1	S	-0.53
2	Ag	0.27
3	Ag	0.27
4	Ag	0.27
5	Ag	0.27

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	2.150
Interband polarizability (y) [Å]	2.150
Interband polarizability (z) [Å]	0.258

Infrared polarizability

Static polarizability [Å]
Phonons only (x)	0.20
Phonons only (y)	0.20
Phonons only (z)	0.00
Total (phonons + electrons) (x)	2.35
Total (phonons + electrons) (y)	2.35
Total (phonons + electrons) (z)	0.26

Miscellaneous

Miscellaneous details
Unique ID	2SAg2-1
Number of atoms	6
Number of species	2
Formula	Ag4S2
Reduced formula	Ag2S
Stoichiometry	AB2
Unit cell area [Å2]	34.649
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree_Wang23/AB2/SAg2/S2Ag4-f5e361ed59c5
Old uid	S2Ag4-b7ce19981b42
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]	2.490
Structure origin	Wang23
Band gap (PBE) [eV]	1.686
Direct band gap (PBE) [eV]	1.686
gap_dir_nosoc	1.762
Vacuum level [eV]	2.194
Fermi level wrt. vacuum (PBE) [eV]	-4.859
Valence band maximum wrt. vacuum (PBE) [eV]	-5.702
Conduction band minimum wrt. vacuum (PBE) [eV]	-4.016

Miscellaneous details
minhessianeig	-0.000
Dynamically stable	Yes
Band gap (HSE06) [eV]	2.619
Direct band gap (HSE06) [eV]	2.619
Fermi level wrt. vacuum (HSE) [eV]	-5.270
Valence band maximum wrt. vacuum (HSE06) [eV]	-6.579
Conduction band minimum wrt. vacuum (HSE06) [eV]	-3.960
Interband polarizability (x) [Å]	2.150
Interband polarizability (y) [Å]	2.150
Interband polarizability (z) [Å]	0.258
Static polarizability (phonons) (x) [Å]	0.203
Static polarizability (phonons + electrons) (x) [Å]	2.353
Static polarizability (phonons) (y) [Å]	0.204
Static polarizability (phonons + electrons) (y) [Å]	2.354
Static polarizability (phonons) (z) [Å]	0.002
Static polarizability (phonons + electrons) (z) [Å]	0.260
Energy [eV]	-19.967
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]	0.000
Heat of formation [eV/atom]	-0.075