Periodic Hartree-Fock and Hybrid Functionals in DFTK

We implemented exact exchange in the periodic and plane wave based DFTK code.

This exact exchange (EXX) implementation enables Hartree-Fock and hybrid functional calculation (PBE0, HSE) for periodic systems and comes with the following features:

• spin-restricted and unrestricted EXX
• Adaptively Compressed Exchange (ACE)
• restriction to \(\mathbf \Gamma\)-point sampling of the Brillouine zone
• various techniques to treat the Coulomb singularity at \(G+q=0\):
  • Probe charge Ewald
  • Wigner-Seitz truncation
  • Spherical truncation
  • Voxel averaging

Check the example file in DFTK.