A simple tool for plane-wave kinetic energy cutoff (encut) and kmesh convergence tests for density functional theory (DFT) calculations.

The main features include:

1. A script to generate INCAR and KPOINTS files

   • Using the input parameters provided, INCAR and KPOINTS files are created. (Note: The ENCUT for the INCAR file will be used for kmesh convergence tests and the kmesh for the KPOINTS file will be used for cutoff/encut convergence tests.)

2. A script to create folders for cutoff and kmesh convergence, and update the cutoff and kmesh values in each INCAR and KPOINTS file

3. Plotting script to create cutoff and kmesh convergence plots.

   • VASP calculations are imported using Pymatgen (energies extracted from vasprun.xml files)

The code currently primarily supports VASP calculations.

The scripts are intended to be used via the command-line. The built-in help (--help) option for each command provides a summary of available options.

Currently, the commands provided are:

-generate_files: For generating INCAR and KPOINTS input files.
-generate_folders: For creating folders for cutoff and kmesh convergence tests, copying the files, and updating the cutoff and kmesh values. (Note: POSCAR (structure file) and POTCAR (pseudopotential file) need to be present in the folder for this command to work.)
-analyse_conv: For extracting energies from VASP calculations, creating csv files, and plotting the convergence data. (Note: The command uses vasprun.xml files to extract energies and so complete DFT calculations performed using VASP is a prerequisite.)

The command-line scripts are written in Python and require the following packages: