{"id":{"repo_id":"cornell","oai_identifier":"oai:ecommons.cornell.edu:1813/67261"},"canonical_url":"https://search.dev.ndltd.org/etd/cornell/oai:ecommons.cornell.edu:1813/67261","repository":{"repo_id":"cornell","name":"Cornell University","base_url":"https://ecommons.cornell.edu/server/oai/request"},"display":{"title":"Semiclassical Approaches to Complex Chemical Simulation in Real Time","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.","abstract_html":"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.","abstract_has_math":false,"creators":["Church, Matthew Steven"],"institution":"Cornell University","degree_name":"Ph.D., Chemistry and Chemical Biology","degree_level":"Doctor of Philosophy","degree_discipline":"Chemistry and Chemical Biology","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":["Loring, Roger F.","Ezra, Gregory Sion"],"year":2019,"date_issued":"2019-05-30","date_published":"2019-05-30","updated_at":"2026-07-24T01:49:06Z","subjects":["Quantum Mechanics","Physical chemistry","Computational Chemistry","chemical physics","initial value representation","semiclassical dynamics","theoretical chemistry"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7298/fys0-3128"],"render_values":[{"text":"https://doi.org/10.7298/fys0-3128","href":"https://doi.org/10.7298/fys0-3128","code":true}]},{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["ProQuest Submission ID: 11376","ProQuest Publication ID: 13878728"],"render_values":[{"text":"ProQuest Submission ID: 11376","href":null,"code":true},{"text":"ProQuest Publication ID: 13878728","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/1813/67261","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Loring, Roger F.","Ezra, Gregory Sion"]},{"key":"dc:creator","label":"Author","values":["Church, Matthew Steven"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2019-10-15T15:28:45Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2019-10-15T15:28:45Z"]},{"key":"dc:date.issued","label":"Date","values":["2019-05-30"]},{"key":"dc:type","label":"Dc Type","values":["dissertation or thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry and Chemical Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctor of Philosophy"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D., Chemistry and Chemical Biology"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Cornell University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Quantum Mechanics","Physical chemistry","Computational Chemistry","chemical physics","initial value representation","semiclassical dynamics","theoretical chemistry"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7298/fys0-3128"]},{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["ProQuest Submission ID: 11376","ProQuest Publication ID: 13878728"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/1813/67261"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Semiclassical Approaches to Complex Chemical Simulation in Real Time"]}]}],"canonical_facts":{"dc:contributor.committeemember":["Loring, Roger F.","Ezra, Gregory Sion"],"dc:creator":["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: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:format.mimetype":["application/pdf"],"dc:identifier.doi":["https://doi.org/10.7298/fys0-3128"],"dc:identifier.other":["ProQuest Submission ID: 11376","ProQuest Publication ID: 13878728"],"dc:identifier.uri":["https://hdl.handle.net/1813/67261"],"dc:language.iso":["en_US"],"dc:subject":["Quantum Mechanics","Physical chemistry","Computational Chemistry","chemical physics","initial value representation","semiclassical dynamics","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_level":["Doctor of Philosophy"],"thesis:degree_name":["Ph.D., Chemistry and Chemical Biology"],"thesis:institution_name":["Cornell University"]},"updated_at":"2026-07-24T01:49:06Z"}