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Structure info
Layer group pmmn
Layer group number 46
Structure origin Wang23
Stability
Energy above convex hull [eV/atom] 0.095
Heat of formation [eV/atom] -0.951
Dynamically stable Yes
Basic properties
Magnetic No
Band gap (PBE) [eV] 0.608
Band gap (HSE06) [eV] 1.917
XYZ CIF JSON
Axis x [Å] y [Å] z [Å] Periodic
1 7.759 2.210 0.000 Yes
2 4.830 5.020 0.000 Yes
3 0.000 -0.000 17.515 No
Lengths [Å] 8.068 6.966 17.515
Angles [°] 90.000 90.000 30.209

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 K4O2
Stoichiometry AB2
Number of atoms 6
Unit cell area [Å2] 28.279
Thickness [Å] 2.506

O2K4 (2OK2-2)
Heat of formation [eV/atom] -0.95
Energy above convex hull [eV/atom] 0.10
Monolayers from C2DB
O2K4 (2OK2-1) -0.99 eV/atom
O2K4, (2OK2-2) -0.95 eV/atom
K4O12 (4KO3-1) -0.69 eV/atom
K (1K-1) 0.26 eV/atom
Bulk crystals from OQMD123
K4O4 -1.08 eV/atom
K2O -1.05 eV/atom
KO2 -0.86 eV/atom
K4O12 -0.64 eV/atom
K4 0.00 eV/atom
O8 0.00 eV/atom

AB2/2OK2/2/phonon_bs.png
Minimum eigenvalue of Hessian [eV/Ų] -0.00

Cij (N/m) xx yy xy
xx 16.31 7.23 -0.54
yy 7.48 16.47 0.08
xy -0.56 0.16 20.33
Stiffness tensor eigenvalues
Eigenvalue 0 9.02 N/m
Eigenvalue 1 20.33 N/m
Eigenvalue 2 23.77 N/m

Key values [eV]
Band gap (PBE) 0.608
Direct band gap (PBE) 0.608
Valence band maximum wrt. vacuum (PBE) -1.922
Conduction band minimum wrt. vacuum (PBE) -1.314
DOS BZ

Key values [eV]
Band gap (HSE06) 1.917
Direct band gap (HSE06) 1.951
Valence band maximum wrt. vacuum (HSE06) -3.136
Conduction band minimum wrt. vacuum (HSE06) -1.218

ZKij ux uy uz
Px 1.02 -0.03 0.12
Py -0.03 1.02 0.12
Pz 0.08 0.08 0.23
ZKij ux uy uz
Px 1.02 -0.03 0.12
Py -0.03 1.02 0.12
Pz 0.08 0.08 0.23
ZOij ux uy uz
Px -2.05 0.07 0.00
Py 0.07 -2.04 0.00
Pz 0.00 -0.00 -0.45
ZKij ux uy uz
Px 1.02 -0.03 -0.12
Py -0.03 1.02 -0.12
Pz -0.08 -0.08 0.23
ZKij ux uy uz
Px 1.02 -0.03 -0.12
Py -0.03 1.02 -0.12
Pz -0.08 -0.08 0.23
ZOij ux uy uz
Px -2.05 0.07 -0.00
Py 0.07 -2.04 -0.00
Pz -0.00 0.00 -0.45

Atom No. Chemical symbol Charges [|e|]
0 K 0.73
1 K 0.73
2 K 0.73
3 K 0.73
4 O -1.47
5 O -1.47

AB2/2OK2/2/berry-phases0.png

AB2/2OK2/2/rpa-pol-x.png AB2/2OK2/2/rpa-pol-z.png
AB2/2OK2/2/rpa-pol-y.png
Properties
Interband polarizability (x) [Å] 1.410
Interband polarizability (y) [Å] 1.411
Interband polarizability (z) [Å] 0.400

Miscellaneous details
Unique ID 2OK2-2
Number of atoms 6
Number of species 2
Formula K4O2
Reduced formula K2O
Stoichiometry AB2
Unit cell area [Å2] 28.279
Original file-system folder /home/niflheim2/cmr/C2DB-ASR/tree_Wang23/AB2/OK2/O2K4-2630fb3a86b1
Old uid O2K4-99e16c640c76
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] 2.506
Structure origin Wang23
Band gap (PBE) [eV] 0.608
Direct band gap (PBE) [eV] 0.608
gap_dir_nosoc 0.608
Vacuum level [eV] 1.362
Miscellaneous details
Fermi level wrt. vacuum (PBE) [eV] -1.618
Valence band maximum wrt. vacuum (PBE) [eV] -1.922
Conduction band minimum wrt. vacuum (PBE) [eV] -1.314
minhessianeig -0.000
Dynamically stable Yes
Band gap (HSE06) [eV] 1.917
Direct band gap (HSE06) [eV] 1.951
Fermi level wrt. vacuum (HSE) [eV] -2.177
Valence band maximum wrt. vacuum (HSE06) [eV] -3.136
Conduction band minimum wrt. vacuum (HSE06) [eV] -1.218
Interband polarizability (x) [Å] 1.410
Interband polarizability (y) [Å] 1.411
Interband polarizability (z) [Å] 0.400
Energy [eV] -20.830
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] 0.095
Heat of formation [eV/atom] -0.951