Reactive Molecules at Ultra-low Temperatures

This lecture covers the use of advanced path integral techniques to study reactive molecules at ultra-low temperatures, focusing on molecules solvated in helium. The instructor explains experimental techniques like HENDI spectroscopy and He tagging photodissociation spectroscopy, followed by simulations using hybrid PIMD/PIMC procedures and high-dimensional neural network potential energy surfaces. Benchmarking with the Zundel cation and structural properties such as proton sharing coordinates are discussed. The lecture concludes with the application of colored noise thermostats for accelerated convergence and the challenges of simulating anharmonic cases at ultra-low temperatures.