VASP the GUIDE: Hartree-Fock (HF) type and hybrid functional calculations
VASPwiki: Tutorial on hybrid functionals
Related discussion: How can I calculate the DOS by using HSE06 in vasp?
These instructions are taken from the Vasp forum
Band structures using hybrid functionals have to be calculated the following way:
First perform a selfconsistent Hartree-Fock/HSE calculation using a conventional KPOINTS file.
Copy the IBZKPT file to KPOINTS, and explicitely add all desired k-points along high-symmetry lines of the BZ that are needed for the bandstructure plot. Add the points at the end of the KPOINTS file, but set the weights of these added k-points to 0.
Do not forget to set the number of k-points in KPOINTS correctly (to the number of the k-points used in the standard mesh PLUS the number of the k-points along the lines), such that all k-points are used for the calculations.
NKRED can not be used.
Perform a second VASP run:
It is recommended to use the Davidson algorithm, since it converges that eigen energies at the new k-points fastest. Since VASP terminates when the total energy is converged to a certain threshold, it is important to force VASP to do a minimum number of steps, so that the orbitals at the new k-points are fully converged (note: since their weight is zero, they do not contribute to the total energy). This can be done using e.g.12ALGO = N ; NELMIN = 5 ! Davidson, minimum 5 scf-stepsIMIX = 1 ! Use simple charge mixer, since
Pulay might blow up
The KS-eigenvalues of the states along the high-symmetry lines are written in OUTCAR, EIGENVAL, vasprun.xml; please cut the k-points required for the bandstructure from one of these files and proceed as usual (using p4vasp or any other graphics tool you usually use to produce bandstructure-plots)
Note: A Hartee-Fock calculation can NOT be continued from an existing CHGCAR file, since the non-local exchange is not determined by the charge density but by the density matrix and/or the KS-orbitals.
After structural optimization
- Use script
symlto output file
inp.kpt. If the file has a few lines of zero, then delete.
- Add the contents of
inp.kptat the end of the IBZKPT file, set the weights of these added k-points to 0.
- Set the number of k-points correctly. For this example, the number is 1 + rows of file
- Copy the IBZKPT file to KPOINTS.
Submit the job, then the EIGENVAL file will generate after the calculation. Modify the contents of the EIGENVAL: Remove high symmetry points whose weights are not zero and set the number of k-points correctly.
pbnf.x to output file
highk.dat. Import the data into origin and plot band structure.
NOTE: There is a problem. In the step Hseband, the ICHARG parameter in the INCAR file needs to be set to 11 or 2? This needs to be tested.
Related discussion: http://muchong.com/t-3723568-1 http://muchong.com/t-4232787-1