Vienna Ab initio Simulation Package 6.5.1

The Vienna Ab initio Simulation Package or VASP is a package for performing quantum mechanical molecular dynamics (MD) using quasi-potentials and a smooth wave cutoff. The approach implemented in VASP is based on a temperature-limited local density approximation (with free energy as a variable) and an accurate evaluation of the instantaneous electronic ground state at each MD step using effective matrix schemes and Pulay mixing schemes. .

These techniques avoid all the problems in the original Car-Parrinello method, which is based on simultaneous integration of the electron and ion equations of motion. The interaction between ions and electrons is described using Vanderbilt ultrasoft pseudopotentials (US-PP) or the advanced projector wave (PAW) method.

Both techniques allow a significant reduction of the number of waves per atom for transition metals and first-row elements. Forces and stress can be easily calculated with VASP and used to relax the atoms in their moment fields.

Features and features of the Vienna Ab initio Simulation Package:

• Dynamics and relaxation: Oppenheimer molecular dynamics, relaxation using conjugate gradient, closed molecular dynamics, dimer climbing (transition state search)
• Linear response to electric fields: static dielectric properties, piezoelectric tensors (including ionic)
• Optical properties: frequency-dependent dielectric degradation in independent particle approximation, frequency-dependent tensor in RPA and TD-DFT, Cassida equation for TD-DFT and TD-Hartree-Fock
• Magnetism: approach of finite magnetic moments
• Linear response to ionic displacement: elastic constants (including ionic), internal stress tensors
• Berry steps: macroscopic polarization and limited electric fields.