A comparison of Car-Parrinello and Born-Oppenheimer generalized valence bond molecular dynamics

Two methods for performing ab initio molecular dynamics using a generalized valence bond electronic wave function are compared: the Car-Parrinello and Born-Oppenheimer approaches. These techniques differ in how they generate a new electronic wave function at each time step. In the Car-Parrinello scheme, the wave function parameters are propagated as classical degrees of freedom, while in the Born-Oppenheimer scheme the equations describing the wave function are solved at each time step. It is found that trajectories obtained utilizing the Born-Oppenheimer approach are both more accurate and less costly than their Car-Parrinello counterparts for wave functions expressed in terms of atom-centered basis sets.