utils4VASP: Setup and Evaluation of Electronic Structure and Machine-Learned Interatomic Potential Simulations with VASP

We present an open-source collection of scripts and programs for the setup, management and evaluation of calculations with the Vienna ab initio simulation package (VASP), called utils4VASP. It contains 14 independent Python scripts and Fortran programs, all with a unified and intuitive handling concept based on command-line arguments. A large repertoire of VASP calculations can be set up with some simple command line calls, including the generation and combination of POSCAR files for bulk and surface slab structures, the respective POTCAR and KPOINTS files and task-specific INCAR files. It further enables the management and evaluation of complex setups not covered by other utility scripts or programs so far, like split-up and parallelized frequency calculations for large structures, or the automated evaluation and visualization of core level energy or Bader partial charge calculations. Emphasis is made on surface-science related calculations, like the targeted placement of adsorbates on substrates or the visualization of scanning-tunneling microscope pictures. Finally, the generation and management of machine-learned interatomic potentials (MLIPs) based on VASP reference data is greatly simplified. Training data collected by on the fly learnings of VASP ML force fields can be effectively selected and combined, or exported into data formats used for Behler-Parrinello neural network or message-passing atomic cluster expansion (MACE) MLIPs. In this publication, all features within utils4VASP are presented concisely, giving both theoretical background and application examples.