Lab Home | Phone | Search
	Center for Nonlinear Studies
	Home  ▶ People   Current   Executive Committee   Postdocs   Visitors   Students   Research   Publications  ▶ Conferences   Workshops   Sponsorship  ▶ Talks   Seminars   Postdoc Seminars Archive   Quantum Lunch   Quantum Lunch Archive   P/T Colloquia   Archive   Ulam Scholar     Postdoc Nominations  ▶ Student Requests   Student Program  ▶ Visitor Requests   Description   Past Visitors  ▶ Services   General     History of CNLS     Maps, Directions   CNLS Office   T-Division   LANL				Tuesday, September 06, 20163:30 PM - 4:30 PMCNLS Conference Room (TA-3, Bldg 1690) Q-Mat Seminar Development and Applications of a Spin-Symmetry Breaking Algorithm for Ab Initio Non-adiabatic Molecular Dynamics Jordan VincentUC Irvine We explore the role of non-adiabatic effects on acetaldehyde (CH3CHO) photodissociation mechanisms using ab initio non-adiabatic molecular dynamics simulations. The photodissociation is simulated using linear-response time-dependent density functional theory by propagating the trajectories on the S1 and S0 potential energy surfaces and the non-adiabatic effects are taken into account using Tully's surface hopping algorithm. To describe mechanisms involving open-shell intermediates and products, i.e., homolytic dissociation of sigma-bonds, we developed and employ a novel spin-symmetry breaking algorithm. Comparisons between ensembles initiated in the ground and excited states shows that the non-adiabatic effects play only a minor role in reproducing the experimental branching ratios but may have significant contribution on the atomistic level mechanisms. Additionally, a new concerted triple-fragmentation mechanism is identified and non-adiabatic effects on the "roaming" mechanism for methane production are discussed. Host: Tammie Nelson