This page gives hints on how to use hybrid functionals with the ABINIT package.
The Fock exchange term has been implemented in ABINIT, both in the norm-
conserving pseudopotential framework and in the PAW one. Some details about
the implementation in ABINIT can be found here.
For an ABINIT user, to make a calculation of Fock exchange:
- do a first GGA dataset for the ground state
- do a second dataset for the Fock calculation choosing ixc=40-42 (HF, PBE0, PBE0-⅓), -402 (B3LYP-Libxc), -406 (PBE0-Libxc), -456 (PBE0-⅓ Libxc), or -427, -428 (HSE03, HSE06).
The energy, forces and stresses are available in the norm-conserving and PAW
A one-shot G0W0 calculation can follow, only in the norm-conserving case at present.
Use istwfk=1, iscf=2, paral_kgb=0, paral_atom=0.
The efficiency of the calculation is not optimal. Work is in progress concerning this point.
Related Input Variables¶
- ixc Index of eXchange-Correlation functional
- fockoptmix FOCK operator: OPTions for MIXing
- auxc_ixc AUxiliary XC functional for hybrid functional, IXC number
- auxc_scal AUxiliary XC functional for hybrid functional- SCALing factor
- fock_icutcoul Integer that governs the CUT-off for COULomb interaction
- fockdownsampling FOCK operator, k-grid DOWNSAMPLING
- nbandhf Number of BANDs for (Hartree)-Fock exact exchange
- nphf Number of Processors for (Hartree)-Fock exact exchange
- wfmix WaveFunctions MIXing factor
- hyb_mixing HYBrid MIXING coefficient for unscreened fock operator
- hyb_mixing_sr HYBrid MIXING coefficient for Short-Range screened fock operator
- hyb_range_dft HYBrid RANGE for the DFT leftover from the screened fock operator
- hyb_range_fock HYBrid RANGE for the screened FOCK operator
- ixc_sigma Index of eXchange-Correlation functional used for self-energy calculations (SIGMA)
- nkpthf Number of K - Points for (Hartree) Fock exact exchange
- nnsclohf Number of Non-Self Consistent LOops for (Hartree)-Fock exact exchange
- %usefock USE FOCK exact exchange
Selected Input Files¶