VASP Preparation

This guide is here to help you prepare VASP Calculations to be used with pyprocar.

  • Required files : PROCAR, OUTCAR (optional), KPOINTS (optional)

  • flag : code=’vasp’ (default)

In the VASP code, the wavefunction projection information is written into the PROCAR file when LORBIT=11 is set in the INCAR file. For band unfolding, set LORBIT=12 to include phase projections of the wave functions. An OUTCAR file is required to extract the Fermi-energy and reciprocal lattice vectors. If a KPOINTS file is provided, the \(k\)-path will automatically be labeled in the band structure. To perform spin colinear calculations set ISPIN = 2 in the INCAR. To perform spin non-colinear calculations set ISPIN = 2 and LNONCOLLINEAR = .TRUE..

First perform a self-consistent calculation with a \(k\)-mesh grid. Then set ICHARG=11 in the INCAR and create a KPOINTS file containing the :math:-k-path. This can be done with the K Path feature in PyProcar.

Preparing Calculations

To use VASP with QE, one has to run various calculations in independent directories. Here, we will show examples for the different calculations.

Band Structure

  1. Create directory called scf.

  2. Perform self-consistent calculation in this scf directory.

  3. Create directory called bands.

  4. Move the CHGCAR file in the scf directory to the bands directory

  5. Create a KPOINTS file containing the :math:-k-path. This can be done with the K Path feature in PyProcar.

  6. Make sure to set LORBIT=11 or LORBIT=12 for the INCAR in bands directory

  7. Perform a non-self consistent calculation in the bands by setting ICHARG=11 in the INCAR.

  8. Run pyprocar.bandsplot(dirname = ‘bands’ ,mode = ‘plain’, code = ‘vasp’)

Density of States

  1. Create directory called scf.

  2. Perform self-consistent calculation in this scf directory.

  3. Create directory called dos.

  4. Move the CHGCAR file in the scf directory to the dos directory.

  5. Make sure there is a kmesh in the KPOINTS file in the dos directory.

  6. Make sure to set LORBIT=11 or LORBIT=12 for the INCAR in dos directory

  7. Perform a non-self consistent calculation in the dos by setting ICHARG=11 in the INCAR.

  8. Run pyprocar.dosplot(dirname = ‘bands’ ,mode = ‘plain’, code = ‘vasp’)

Band Structure and Density of States

  1. Run the band structure and dos calculation as stated above

  2. Run pyprocar.bandsdosplot(bands_dirname = ‘bands’, dos_dirname = ‘dos’, bands_mode = ‘plain’, dos_mode = ‘plain’, code = ‘vasp’)

Fermi

  1. Create directory called scf.

  2. Perform self-consistent calculation in this scf directory.

  3. Create directory called fermi.

  4. Move the CHGCAR file in the scf directory to the fermi directory.

  5. Make sure there is a kmesh in the KPOINTS file in the fermi directory.

  6. Make sure to set LORBIT=11 or LORBIT=12 for the INCAR in fermi directory

  7. Perform a non-self consistent calculation in the fermi by setting ICHARG=11 in the INCAR.

  8. Run pyprocar.FermiHandler(dirname = ‘fermi’, code = ‘vasp’)

K-Points Format

The \(k\)-path can be specified in KPOINTS which is used for the band structure calculation. Here is an example with \(k\)-path

50 ! Grid points
Line_mode
reciprocal
0.0 0.0 0.0 ! GAMMA
0.5 -0.5 0.5 ! H

0.5 -0.5 0.5 ! H
0.0 0.0 0.5 ! N

0.0 0.0 0.5 ! N
0.0 0.0 0.0 ! GAMMA

0.0 0.0 0.0 ! GAMMA
0.25 0.25 0.25 ! P

0.25 0.25 0.25 ! P
0.5 -0.5 0.5 ! H

0.25 0.25 0.25 ! P
0.0 0.0 0.5 ! N

Magnetic Calculations

Magnetic calculations follow the same steps as above, but it requires additional parameters

Colinear-Spin To perform spin colinear calculations set ISPIN = 2 in the INCAR.

Non-colinear-Spin To perform spin non-colinear calculations set ISPIN = 2 and LNONCOLLINEAR = .TRUE..