UCLA

A hydrated electron is formed when an excess electron is captured and stablized by an aqueous solution. It is generally believed that the electron carves out a quasi-spherical cavity in water and resides in it, but recent simulation work has shown a different picture where the electron is softer and the wavefunction overlaps with water molecules in the inner solvation shell. This thesis explores predictions of these two models for both the transient absorption spectroscopy and the time-resolved photoelectron spectroscopy of photo-excited hydrated electrons, providing direct comparison with experimental results. It has been shown that the non-cavity model does a better job of explaining the non-adiabatic dynamics and temperature dependent behavior of a hydrated electron in its excited state.

This thesis also includes a new attempt using range-separated hybrid functional based ab initio molecular dynamics for small water clusters with an excess electron. The negatively charged water clusters have been studied as a nano-scale version of the hydrated electron and their properties can be extrapolated to bulk solutions. Here the \textit{ab initio} molecular dynamics scheme is demonstrated to perfectly reproduce the spectral signatures of small water cluster anions, thus paving the way for more detailed simulations for bulk hydrated electron.