SYSTEM = ZnO HSE06 ENCUT = 520 ISMEAR = -5 # Tetrahedron method for DOS SIGMA = 0.05 PREC = Accurate LHFCALC = .TRUE. HFSCREEN = 0.2 AEXX = 0.25 GGA = PE ALGO = Damped TIME = 0.4

KPOINTS: Automatic generation 0 Gamma 4 4 2 0 0 0

In this post, I’ll break down what HSE06 is, how to set it up in VASP, and when it’s actually worth the pain. HSE06 is a screened hybrid functional. It mixes 25% exact (Hartree-Fock) exchange with 75% PBE exchange at short range, while keeping PBE correlation.

In older VASP versions (pre-6), you needed LHFCALC = .TRUE. and HFSCREEN = 0.2 . In VASP 6+, you can also use HSE06 as a pseudopotential flag, but the manual INCAR approach is safer. Step 2: FFT grids and precision Hybrid functionals are sensitive to the real-space grid. Use high precision:

If you have spent any time running density functional theory (DFT) calculations, you know the drill: PBE (Perdew-Burke-Ernzerhof) is fast, reliable, and often... wrong. It systematically underestimates band gaps, over-delocalizes electrons, and struggles with strongly correlated materials.