Hse06 Vasp Extra Quality -
Enter (Heyd-Scuseria-Ernzerhof). This hybrid functional has become the gold standard for "affordable accuracy" in solid-state physics. But let’s be real—it comes at a computational cost.
ALGO = Damped # Damped algorithm (often more stable than Normal) TIME = 0.4 # Mixing time (increase from default 0.1) BMIX = 0.0001 # Small mixing parameter AMIN = 0.01 # Avoid Pulay collapse If still failing, try ALGO = All (fast but memory hungry) or IALGO = 53 (very stable but slow). | System | PBE wall time | HSE06 wall time | Memory | | :--- | :--- | :--- | :--- | | Si (8 atoms, 6x6x6 kpoints) | 2 min | 20 min | 2x | | TiO₂ (12 atoms, 4x4x4) | 5 min | 1.5 hours | 3x | | NiO (8 atoms, 8x8x8) | 3 min | Fails / 4 hours | 5x | hse06 vasp
KPOINTS: Automatic generation 0 Gamma 4 4 2 0 0 0 Enter (Heyd-Scuseria-Ernzerhof)
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. ALGO = Damped # Damped algorithm (often more
Why "screened"? Because in a metal, the Coulomb interaction dies off quickly. HSE06 introduces a screening parameter ($\omega$) to cut off the long-range HF exchange, making it computationally feasible for periodic systems.