The premise of the work that was undertaken in this thesis is the use of
mathematical modelling techniques to solve fundamental questions in quantum chemistry. In particular, this project focusses on how thermalisation effects, particularly in the context of proton transfer, can be incorporated into
the exact quantum dynamics method MCTDH, which is the multiconfigurational time-dependent Hartree method. This is a computational method
set up to solve the time-dependent Schr¨odinger equation (TDSE) exactly for
small systems or molecules.
The question posed in this thesis is what can scientists do when the gas
phase zero temperature picture is no longer a useful description for the reactions and processes that we are interested in. For instance, if we look at
proton transfer, there is still a lot of uncertainty about the exact mechanism and the role that is played by the environment in this process. In this
project ML-�-MCTDH is developed and applied in three studies of proton
transfer, looking first at a model of symmetric proton transfer, followed by
a brief study of salicylaldimine and finally looking at porphycene. Chapter
1 introduces the topic and chapters 2 and 3 cover the theory and methodology underpinning the research focus. In the remaining chapters results are
presented and discussed.