History of VASP

A brief history of the development of VASP:

• VASP is based on a program initially written by Mike Payne at the MIT. Hence, VASP has the same roots as the CASTEP/CETEP code, but branched from this root at a very early stage. At the time, the VASP development was started the name CASTEP was not yet established. The CASTEP version upon which VASP is based only supported local pseudopotentials and a Car-Parrinello type steepest descent algorithm.
• July 1989: Jürgen Hafner brought the code to Vienna after half a year stay in Cambridge.
• Sep. 1991: work on the VASP code was started. At this time, in fact, the CASTEP code, was already further developed, but VASP development was based on the old 1989 CASTEP version.
• Oct. 1992: ultra-soft pseudopotentials were included in the code, the self-consistency loop was introduced to treat metals efficiently.
• Jan 1993: J. Furthmüller joined the group. He wrote the first version of the Pulay/Broyden charge density mixer and contributed - among other things - the symmetry code, the INCAR-reader and a fast 3D-FFT.
• Feb 1995: J. Furthmüller left Vienna. In the time due, VASP has got it's final name, and had become a stable and versatile tool for ab initio calculations.
• Sep. 1996: conversion to Fortran 90 (VASP.4.1). The MPI (message passing) parallelisation of the code was started at this time. J.M. Holender, who initially worked on the parallelisation, ``unfortunately'' copied the communication kernels from CETEP to VASP. This was the second time developments originating from CASTEP were included in VASP, which subsequently caused quite some understandable anger and uproar.

• Most of the work on the parallelisation was done in Keele, Staffordshire, UK by Georg Kresse. MPI parallelisation was finished around January 1997. Around July 1998, the communication kernel was completely rewritten (even 3D-FFT) in order to remove any CETEP remainders. Unfortunately, this implied giving up special support for T3D/T3E shmem communication. Since than, VASP is no longer particularly efficient on the T3D/T3E.
• July 1997-Dec. 1999: the projector augmented wave (PAW) method was implemented.
• 2004: The development on the vasp.5.X branch started, including support for Hartree-Fock, $GW$, linear response theory. Despite the initial announcement, vasp.5.X is only a ``mild'' upgrade of vasp.4.6. Internal data structures are largely unchanged.

In addition, the following people have contributed to the code: The tetrahedron integration method was copied from a LMTO-program (original author unknown, but it might be Jepsen or Blöchl). The communication kernels were initially developed by Peter Lockey at Daresbury (CETEP), but they have been subsequently modified completely. The kernel for the parallel FFT was initially written by D. White and M. Payne, but it has been rewritten from scratch around July 1998. Several parts of VASP were co-developed by A. Eichler, and other members of the group in Vienna. David Hobbs worked on the non collinear version. Martijn Marsman has written the routines for calculating the polarisation using the Berry phase approach, spin spirals and Wannier functions. He also rewrote the LDA+U routines initially written by O. Bengone, and extended the spin-orbit coupling to $f$ electrons. Robin Hirschl implemented the Meta-GGA, and is currently working on the Hartree-Fock support (together with Martijn Marsman and Adrian Rohrbach).