{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/84335"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/84335","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Quantum Mechanical Calculations of Time Correlation Functions for Neat Fluids","abstract":"A more direct calculation using the pair-product approximation to the propagator is also discussed. Using single-step approximations to the propagator, it is shown that real-time correlation functions can be expressed as integrals of smooth functions, and thus can be efficiently evaluated by Monte Carlo methods. Tests on a model anharmonic system coupled to a bath of 25 harmonie oscillators are presented, and in spite of the large number of degrees of freedom associated with such a setting, the method allows direct calculation of correlation functions at intermediate temperatures over short to intermediate time lengths. Initial work into applying the single step propagator methodology to a Lennard-Jones fluid is also discussed. The efforts to evaluate the multidimensional integral associated with the unique matrix elements present in such a high dimensional system are explained, along with preliminary results.","abstract_html":"A more direct calculation using the pair-product approximation to the propagator is also discussed. Using single-step approximations to the propagator, it is shown that real-time correlation functions can be expressed as integrals of smooth functions, and thus can be efficiently evaluated by Monte Carlo methods. Tests on a model anharmonic system coupled to a bath of 25 harmonie oscillators are presented, and in spite of the large number of degrees of freedom associated with such a setting, the method allows direct calculation of correlation functions at intermediate temperatures over short to intermediate time lengths. Initial work into applying the single step propagator methodology to a Lennard-Jones fluid is also discussed. The efforts to evaluate the multidimensional integral associated with the unique matrix elements present in such a high dimensional system are explained, along with preliminary results.","abstract_has_math":false,"creators":["Kegerreis, Jeb Stuart"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemical Physics","degree_department":null,"school":null,"contributors":["Makri, Nancy"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T22:14:00Z","date_published":"2015-09-25T22:14:00Z","updated_at":"2026-07-22T22:26:23Z","subjects":["Chemistry, Physical"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI3362936"],"render_values":[{"text":"(MiAaPQ)AAI3362936","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/84335","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Makri, Nancy"]},{"key":"dc:creator","label":"Author","values":["Kegerreis, Jeb Stuart"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T22:14:00Z","10000-01-01","2009"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemical Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry, Physical"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/84335","(MiAaPQ)AAI3362936"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A more direct calculation using the pair-product approximation to the propagator is also discussed. Using single-step approximations to the propagator, it is shown that real-time correlation functions can be expressed as integrals of smooth functions, and thus can be efficiently evaluated by Monte Carlo methods. Tests on a model anharmonic system coupled to a bath of 25 harmonie oscillators are presented, and in spite of the large number of degrees of freedom associated with such a setting, the method allows direct calculation of correlation functions at intermediate temperatures over short to intermediate time lengths. Initial work into applying the single step propagator methodology to a Lennard-Jones fluid is also discussed. The efforts to evaluate the multidimensional integral associated with the unique matrix elements present in such a high dimensional system are explained, along with preliminary results.","Made available in DSpace on 2015-09-25T22:14:00Z (GMT). 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Using single-step approximations to the propagator, it is shown that real-time correlation functions can be expressed as integrals of smooth functions, and thus can be efficiently evaluated by Monte Carlo methods. Tests on a model anharmonic system coupled to a bath of 25 harmonie oscillators are presented, and in spite of the large number of degrees of freedom associated with such a setting, the method allows direct calculation of correlation functions at intermediate temperatures over short to intermediate time lengths. Initial work into applying the single step propagator methodology to a Lennard-Jones fluid is also discussed. The efforts to evaluate the multidimensional integral associated with the unique matrix elements present in such a high dimensional system are explained, along with preliminary results.","Made available in DSpace on 2015-09-25T22:14:00Z (GMT). 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