Car Parrinello Molecular Dynamics

Car-Parrinello molecular dynamics combines two major techniques used in computational chemistry. Molecular dynamics is used for the simulation of the time evolution of systems on an atomistic scale. The simulation include temperature and pressure effects and allow for a direct link to statistical physics and thermodynamics. Density functional theory provides an accurate description of the chemical bonding in many systems. The absence of adjustable parameters make it a transferable method with high predictive power.

a) Method Development
Extensions to standard density functional theory to include excited states are investigated. The restricted open-shell Kohn-Sham method is a simple method that allows the calculation of the lowest excited singlet state. This method was combined efficiently with Car-Parrinello molecular dynamics.
Time-dependent density functional theory (TDDFT) is a complete extension of the original theory. We explore the possibilities of linear response theory within TDDFT to describe excited states. All new methods are implemented into the CPMD computer code (www.cpmd.org)

b) Applications
Molecular dynamics simulations provide detailed insight into dynamical and structural properties of hydrogen bonded molecular liquids. Chemical reactions in solution and proton transfer in the ground and excited states are studied.