Research Article

Consistent Atomic Geometries and Electronic Structure of Five Phases of Potassium Niobate from Density-Functional Theory

Table 8

Fundamental band gaps for the cubic phase of calculated with different lattice parameters and exchange-correlation functionals (see Figure 4).

Geometry Functional Band gap (eV)

Expt. PBE 1.426

LDA LDA 1.377

PBE PBE 1.426
PBEsol 1.125

PBEsol PBE 1.540
PBEsol 1.396

PBEsol HSE-25 2.701
HSE-29 3.080
HSE-30 3.138
HSE-31 3.194
HSE-32 3.252
HSE-33 3.346
HSE-50 4.176