The transition from a standard PBE calculation to HSE06 requires changes to the INCAR file, and often to KPOINTS and POTCAR .
ENCUT = 1.3 * ENMAX
VASPsol (by Hennig group) can be patched into VASP. To combine with HSE06:
HSE06 mixes exact exchange only into the part, where it matters most for chemical bonding and band gaps. The long-range part is treated with standard PBE exchange. The parameter (\omega) (omega) controls the screening length. In standard HSE06, (\omega = 0.11 , \text\AA^-1). The mixing parameter (\alpha) (alpha) is typically 0.25 (25% exact exchange).
The genius of is the screening trick . The Coulomb potential is split into two parts: short-range (SR) and long-range (LR):
: Benchmarking the band gap tunability of monolayers under pressure.
The exact solution to the Schrödinger equation for many-body systems involves the Hartree-Fock (HF) method, which includes a non-local exact exchange term that cancels self-interaction. However, pure HF calculations tend to overestimate band gaps and lack correlation energy.
Accurately predicting the band edges of materials used in transistors and LEDs.
Because the exchange potential is expensive to calculate, VASP does not update it every single electronic step. Instead, it updates the charge density frequently (inner loop) and updates the exact exchange potential only every few steps (outer loop).
While standard Density Functional Theory (DFT) methods like PBE are efficient, they often fail to predict accurate band gaps. This is where HSE06 steps in, offering a more precise, albeit computationally demanding, alternative. What is VASP?
The Vienna Ab initio Simulation Package (VASP) is a computer program for atomic-scale materials modelling, e.g., electronic structure calculations and quantum-mechanical molecular-dynamics, from first principles. It uses plane-wave basis sets and projector-augmented wave (PAW) methods to solve the Kohn-Sham equations. VASP is widely used in academia and industry to study: