VASP

VASP, short for Vienna Ab initio Simulation Package, is a plane-wave–based first-principles electronic-structure code used to model the properties of materials from density functional theory. It was developed by Georg Kresse and Jürgen Furthmüller at the University of Vienna and is distributed by VASP Software GmbH. VASP is proprietary software that requires a license and is widely used in academia and industry to study solids, surfaces, interfaces, and defects.

Methodology and capabilities: VASP solves the Kohn–Sham equations within a plane-wave basis set using projector-augmented-wave (PAW) or ultrasoft pseudopotentials. It supports spin polarization and spin–orbit coupling, finite-temperature smearing, and a range of exchange–correlation functionals, including LDA, GGA (such as PBE and PBEsol), and hybrids such as PBE0 and HSE06. It also offers DFT+U and various van der Waals corrections. The code can perform geometry optimization, Born–Oppenheimer molecular dynamics, and transition-state searches with NEB and climbing-image NEB.

Input and output: Typical inputs include INCAR (calculation parameters), POSCAR (structure), POTCAR (pseudopotentials), and KPOINTS (k-point mesh). Outputs include OUTCAR and vasprun.xml, as well as CHGCAR, WAVECAR, and CONTCAR files for charge density, wavefunctions, and final structures. VASP is commonly deployed on Linux-based high-performance computing clusters and uses MPI for parallelization, with some OpenMP support.

Applications: VASP is widely used to investigate electronic structure, total energies, phase stability, defect formation, diffusion, vibrational properties, and surface phenomena across metals, ceramics, semiconductors, and molecular systems. It remains a mainstay in computational materials science for exploring structure–property relationships and informing experimental work.