On-the-fly adiabatically switched semiclassical dynamics for vibrational spectroscopy

Semiclassical dynamics is able to reproduce quantum effects from classical dynamics runs, allowing the vibrational study of very large dimensional systems. Adiabatic switching has already proven capable of improving precision and accuracy of semiclassical results of challenging model potentials and small molecular systems. I extended the technique to larger molecular systems, whose semiclassical spectrum is usually collected by means of a single run evolved with ab initio “on-the-fly” calculations. This application has been benchmarked on small molecules and then tested on glycine, improving the pre-existing SC calculations. Finally, this new approach has permitted a preliminary study of the vibrational spectrum of the 17-atom proline, an open problem in theoretical and experimental chemistry.