{"692062":{"#nid":"692062","#data":{"type":"event","title":"Departmental Colloquium - Prof. Joshua Kretchmer (GA Tech)","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle:\u003C\/strong\u003E Real-time simulations of ultrafast electron relaxation dynamics\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EThe Kretchmer group develops simulation methods at the intersection of electronic structure theory and quantum dynamics. We apply our methods to examine electron and spin dynamics, non-adiabatic processes, and charge transport in complex molecular and material systems including weakly-bound molecular clusters, chiral and helical molecules, and perovskites. In this talk, I will highlight our recent development of a new methodology to unravel the competing electronic relaxation pathways following inner-shell ionization in weakly bound systems. When an inner-shell electron is removed, another electron relaxes to fill the vacancy, which can transfer energy to a nearby entity, generating a low-energy secondary ionized electron. Critically, the location of the electron that relaxes and the secondary ionized electron can originate from either the original molecule or a neighboring molecule. The relaxation can also compete with electron, hole, and even proton transfer. Our work combines real-time DFT with a complex absorbing potential to simulate the explicit dynamics of this complex array of processes. We have additionally introduced coupled electron-nuclear dynamics through Ehrenfest dynamics, which enabled an in-depth investigation of the fragmentation pathways in the water dimer following inner-valence ionization. Our simulations identified a previously unknown relaxation channel essential to reproducing the experimentally observed fragmentation products of our collaborators, prompting a reinterpretation of the origin of low-energy electrons in hydrogen-bonded systems such as water.\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EOne in the series of the SoCB seminars.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"School of Chemistry \u0026 Biochemistry - Seminar Series"}],"uid":"35342","created_gmt":"2026-08-27 15:09:34","changed_gmt":"2026-08-27 15:10:56","author":"mcurtis41","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-09-03T15:30:00-04:00","event_time_end":"2026-09-03T16:30:00-04:00","event_time_end_last":"2026-09-03T16:30:00-04:00","gmt_time_start":"2026-09-03 19:30:00","gmt_time_end":"2026-09-03 20:30:00","gmt_time_end_last":"2026-09-03 20:30:00","rrule":null,"timezone":"America\/New_York"},"location":"EBB Krone 1005","extras":[],"hg_media":{"680997":{"id":"680997","type":"image","title":"georgia-tech-ppt-2022-Prof.-Joshua-Kretchmer.png","body":null,"created":"1787843426","gmt_created":"2026-08-27 15:10:26","changed":"1787843426","gmt_changed":"2026-08-27 15:10:26","alt":"JK Seminar","file":{"fid":"265341","name":"georgia-tech-ppt-2022-Prof.-Joshua-Kretchmer.png","image_path":"\/sites\/default\/files\/2026\/08\/27\/georgia-tech-ppt-2022-Prof.-Joshua-Kretchmer.png","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2026\/08\/27\/georgia-tech-ppt-2022-Prof.-Joshua-Kretchmer.png","mime":"image\/png","size":375975,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2026\/08\/27\/georgia-tech-ppt-2022-Prof.-Joshua-Kretchmer.png?itok=hs6urLQX"}}},"media_ids":["680997"],"groups":[{"id":"85951","name":"School of Chemistry and Biochemistry"}],"categories":[],"keywords":[],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1795","name":"Seminar\/Lecture\/Colloquium"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"177814","name":"Postdoc"},{"id":"174045","name":"Graduate students"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EHost:\u003C\/strong\u003E David Sherrill\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}