dc.contributor.author Church, Matthew Steven dc.date.accessioned 2019-10-15T15:28:45Z dc.date.available 2019-10-15T15:28:45Z dc.date.issued 2019-05-30 dc.identifier.other Church_cornellgrad_0058F_11376 dc.identifier.other http://dissertations.umi.com/cornellgrad:11376 dc.identifier.other bibid: 11050242 dc.identifier.uri https://hdl.handle.net/1813/67261 dc.description.abstract Semiclassical (SC) theory offers a pedagogically rich connection between quantum and classical perspectives of nature, and, furthermore, is a promising approach to incorporating quantum effects into molecular dynamics simulations. However, a variety of numerical challenges associated with SC methods, such as the cumbersome search for special trajectories, or the integration of highly oscillatory functions (i.e. the SC sign problem"), generally renders SC theory impractical for all but very simple, low-dimensional systems. In this dissertation we derive a variety of mixed quantum-classical (MQC) representations of the real-time correlation function within the SC initial value representation (SC-IVR) using the modified Filinov filtration (MFF) technique. The most promising of these methods are subsequently tested on a number of low- and high-dimensional systems. Each of these methods have three significant advantages. (1) They offer a significant improvement upon the SC-IVR sign problem." (2) They offer mode-specific quantization in a dynamically consistent framework. And (3) they are significantly easier to implement than other leading SC-IVR methodologies. The extension of these methods to nonadiabatic systems is made as well. We conclude that, in future studies of a variety of non-equilibrium molecular systems, particularly those that exhibit strong nuclear quantum effects such as interference, the novel SC-IVR methods presented here should prove to be very powerful. dc.language.iso en_US dc.subject Quantum Mechanics dc.subject Physical chemistry dc.subject Computational Chemistry dc.subject chemical physics dc.subject initial value representation dc.subject semiclassical dynamics dc.subject theoretical chemistry dc.title Semiclassical Approaches to Complex Chemical Simulation in Real Time dc.type dissertation or thesis thesis.degree.discipline Chemistry and Chemical Biology thesis.degree.grantor Cornell University thesis.degree.level Doctor of Philosophy thesis.degree.name Ph.D., Chemistry and Chemical Biology dc.contributor.chair Ananth, Nandini dc.contributor.committeeMember Loring, Roger F. dc.contributor.committeeMember Ezra, Gregory Sion dcterms.license https://hdl.handle.net/1813/59810 dc.identifier.doi https://doi.org/10.7298/fys0-3128
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