Overview: Ag₂I₂Se₂

Structure info
Layer group	pmmn
Layer group number	46
Structure origin	original03-18

Stability
Energy above convex hull [eV/atom]	0.188
Heat of formation [eV/atom]	0.009
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	3.380	0.000	0.000	Yes
2	-0.000	4.415	0.000	Yes
3	0.000	0.000	21.342	No

Lengths [Å]	3.380	4.415	21.342
Angles [°]	90.000	90.000	90.000

Crystal structure

Symmetries
2D Bravais type	Rectangular (op)
Layer group number	46
Layer group	pmmn
Space group number (bulk in AA-stacking)	59
Space group (bulk in AA-stacking)	Pmmn
Point group	mmm
Inversion symmetry	Yes

Structure data
Formula	Ag2I2Se2
Stoichiometry	ABC
Number of atoms	6
Unit cell area [Å2]	14.923
Thickness [Å]	8.526

Stability

Convex hull

Ag2I2Se2 (2AgISe-1)
Heat of formation [eV/atom]	0.01
Energy above convex hull [eV/atom]	0.19

Monolayers from C2DB
Ag2I2 (2AgI-1)	-0.26 eV/atom
Ag2I2 (2AgI-2)	-0.25 eV/atom
Ag6I6 (6AgI-1)	-0.24 eV/atom
Ag5I5 (5AgI-1)	-0.24 eV/atom
Ag6I6 (6AgI-2)	-0.23 eV/atom
Ag2I2 (2AgI-3)	-0.22 eV/atom
Ag6I6 (6AgI-3)	-0.22 eV/atom
Ag6I6 (6AgI-4)	-0.21 eV/atom
Ag3I3 (3AgI-1)	-0.21 eV/atom
Ag3I3 (3AgI-2)	-0.21 eV/atom
AgI (1AgI-1)	-0.20 eV/atom
Ag2I2 (2AgI-4)	-0.19 eV/atom
Ag6I8 (2Ag3I4-1)	-0.19 eV/atom
I12Ag15 (3I4Ag5-1)	-0.17 eV/atom
Ag6I12 (6AgI2-1)	-0.16 eV/atom
Ag3I5 (1Ag3I5-1)	-0.14 eV/atom
Ag2I6 (2AgI3-1)	-0.13 eV/atom
Ag2I2Se4 (2AgISe2-1)	-0.12 eV/atom
Ag4I8 (4AgI2-1)	-0.12 eV/atom
Ag2I4 (2AgI2-1)	-0.12 eV/atom
Ag2I6 (2AgI3-2)	-0.11 eV/atom
Ag4I8 (4AgI2-2)	-0.10 eV/atom
Ag4I12 (4AgI3-1)	-0.09 eV/atom
Se2Ag4 (2SeAg2-1)	-0.09 eV/atom
Ag4I4Se4 (4AgISe-1)	-0.08 eV/atom
Ag2I4 (2AgI2-2)	-0.08 eV/atom
AgI3 (1AgI3-1)	-0.07 eV/atom
Se8Ag16 (8SeAg2-1)	-0.07 eV/atom
AgI2 (1AgI2-1)	-0.06 eV/atom
AgI2 (1AgI2-2)	-0.06 eV/atom
Ag4Se4 (4AgSe-1)	-0.02 eV/atom
AgSeI2 (1AgSeI2-1)	-0.01 eV/atom
Ag2I2Se2, (2AgISe-1)	0.01 eV/atom
Ag2Se2 (2AgSe-1)	0.02 eV/atom
AgI2 (1AgI2-3)	0.03 eV/atom
Ag8Se12 (4Ag2Se3-1)	0.03 eV/atom
Ag2Se4 (2AgSe2-1)	0.05 eV/atom
Ag2Se2 (2AgSe-2)	0.05 eV/atom
Ag2Se2 (2AgSe-3)	0.06 eV/atom
Ag2I6 (2AgI3-3)	0.07 eV/atom
Ag2I6 (2AgI3-4)	0.07 eV/atom
AgSe2 (1AgSe2-1)	0.11 eV/atom
SeAg2 (1SeAg2-1)	0.15 eV/atom
Ag2Se2 (2AgSe-4)	0.15 eV/atom
Ag2Se2 (2AgSe-5)	0.18 eV/atom
Ag2Se4 (2AgSe2-2)	0.19 eV/atom
Se2 (2Se-1)	0.21 eV/atom
AgSe2 (1AgSe2-2)	0.22 eV/atom
Ag2Se2 (2AgSe-6)	0.27 eV/atom
Se2 (2Se-2)	0.29 eV/atom
Ag2 (2Ag-1)	0.31 eV/atom
AgSe2 (1AgSe2-3)	0.32 eV/atom

Bulk crystals from OQMD123
AgI	-0.27 eV/atom
Ag8Se4	-0.07 eV/atom
Ag4	0.00 eV/atom
I4	0.00 eV/atom
Se3	0.00 eV/atom

Phonons

Minimum eigenvalue of Hessian [eV/Ų]

-3.63

Linear deformations

Stiffness tensor

Cij (N/m)	xx	yy	xy
xx	65.84	24.78	-0.00
yy	31.14	52.54	-0.00
xy	0.00	0.00	-4.49

Stiffness tensor eigenvalues
Eigenvalue 0	-4.49 N/m
Eigenvalue 1	30.62 N/m
Eigenvalue 2	87.75 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)	-5.242

Fermi surface

Electronic properties

Bader charges

Atom No.	Chemical symbol	Charges [|e|]
0	Ag	0.29
1	Ag	0.29
2	Se	-0.14
3	Se	-0.14
4	I	-0.15
5	I	-0.15

Optical properties

Optical polarizability

Properties
Interband polarizability (x) [Å]	123.182
Interband polarizability (y) [Å]	23.383
Interband polarizability (z) [Å]	0.888
Plasma frequency (x) [eV Å0.5]	13.453
Plasma frequency (y) [eV Å0.5]	16.711

Miscellaneous

Miscellaneous details
Unique ID	2AgISe-1
Number of atoms	6
Number of species	3
Formula	Ag2I2Se2
Reduced formula	AgISe
Stoichiometry	ABC
Unit cell area [Å2]	14.923
Original file-system folder	/home/niflheim2/cmr/C2DB-ASR/tree/ABC/AgISe/Ag2I2Se2-007877c871f7
Old uid	Ag2I2Se2-007877c871f7
Space group (bulk in AA-stacking)	Pmmn
Space group number (bulk in AA-stacking)	59
Point group	mmm
Inversion symmetry	Yes
Layer group number	46
Layer group	pmmn
2D Bravais type	Rectangular (op)
Thickness [Å]	8.526
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]	5.293
Fermi level wrt. vacuum (PBE) [eV]	-5.242
minhessianeig	-3.630
Dynamically stable	No
Interband polarizability (x) [Å]	123.182
Interband polarizability (y) [Å]	23.383
Interband polarizability (z) [Å]	0.888
Plasma frequency (x) [eV Å0.5]	13.453
Plasma frequency (y) [eV Å0.5]	16.711
Energy [eV]	-15.550
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]	0.188
Heat of formation [eV/atom]	0.009