Dual-Basis Molecular Dynamics
The dual-basis methods developed during my Ph.D. work significantly accelerate HF, DFT, and MP2 energy and force evaluations. Such work is directly transferable to ab initio molecular dynamics (MD), where forces are evaluated on-the-fly.

We have demonstrated such techniques in an MD context and shown that dual-basis MD is a faithful representation of standard Born-Oppenheimer molecular dynamics. Most notably, demonstrated timings outperformed even an idealized estimate of Car-Parrinello MD without the potential for artificial coupling of electronic and nuclear dynamics.

Application of these methods to the atmospheric activation of water by NO⁺ accurately reproduces the significantly broadened lineshapes in their vibrational spectra. These lineshapes were a qualitative detail lacking in the eigenvalue-based "stick" spectra reported in our previous work. Analysis of the contributing trajectories indicates that "in-out" motion of the flanking waters significantly alters the dominant shared-proton stretch and determines the unique line shapes.


Reference:
"Ab initio molecular dynamics with dual basis set methods"
R. P. Steele, M. Head-Gordon, and J. C. Tully. J. Phys. Chem. A accepted (2010).