Originally, VASP was based on code written by Mike Payne (then at MIT), which was also the basis of CASTEP. It was then brought to the University of Vienna, Austria, in July 1989 by Jürgen Hafner. The main program was written by Jürgen Furthmüller, who joined the group at the Institut für Materialphysik in January 1993, and Georg Kresse. An early version of VASP was called VAMP. VASP is currently being developed by Georg Kresse ; recent additions include the extension of methods frequently used in molecular quantum chemistry to periodic systems. VASP is currently used by more than 1400 research groups in academia and industry worldwide on the basis of software licence agreements with the University of Vienna. Because VASP can be used for a wide range of applications such as phonon calculations and structure calculations, it is widely employed in the fields of condensed matter physics, materials science, and quantum chemistry.