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..