In this talk, we will explore several recent applications of diffusion Monte Carlo to water clusters. Diffusion Monte Carlo is an approach that is well-suited for the evaluation of the ground state wave function and the associated properties. Excited states are more challenging. Through a series of studies, we have shown that the approach is very effective for studying systems like CH5+ or H5O2+ where the couplings between the intermolecular and intramolecular degrees of freedom are either strong or very small. For larger protonated water clusters and neutral water clusters, this is no longer the case, leading to the requirements for long propagation times and much larger ensemble sizes. In this talk we will discuss approaches we have taken to overcome these challenges, along with extensions to methods developed several years ago for exploring spectra based on the ground state properties of the system of interest.

Diffusion Monte Carlo approaches for exploring neutral and protonated water clusters

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.