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    Chemical and Biological and Ben May Seminar

    Date:
    14
    Thursday
    September
    2023
    Lecture / Seminar
    Time: 11:00
    Title: MRSF-TDDFT: Multi-Reference Advantages with The Practicality of Linear Response Theory
    Location: Perlman Chemical Sciences Building
    Lecturer: Prof. Cheol Ho Choi
    Organizer: Ben May Center for Chemical Theory and Computation
    Contact: eli.pollak@weizmann.ac.il
    Abstract: A new quantum theory, MRSF-TDDFT (Mixed-Reference Spin-Flip Time-Dependent Densi ... Read more A new quantum theory, MRSF-TDDFT (Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory) has been developed*, which introduces the multi-reference advantages within the linear response formalism. The density functional theory (DFT) and linear response (LR) time dependent (TD)-DFT are of utmost importance for routine computations. However, the single reference formulation of DFT is suffering from the description of open-shell singlet systems such as diradicals and bond-breaking. LR-TDDFT, on the other hand, finds difficulties in the modeling of conical intersections, doubly excited states, and core-level excitations. Many of these limitations can be overcome by MRSF-TDDFT, providing an alternative yet accurate route for such challenging situations. Now the theory is combined with NAMD, QM/MM, Spin-Orbit Couplings, and Extended Koopman Theorem. Here, we highlight its performances by presenting our recent results by MRSF-TDDFT especially focusing on nonadiabatic molecular dynamics.
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    Ben May Lecutre Series

    Date:
    01
    Thursday
    June
    2023
    Lecture / Seminar
    Time: 14:00-15:00
    Title: Coherence Maps and State-to-State Pathways of Excitation Energy Transfer
    Location: Stone Administration Building
    Lecturer: Prof Nancy Makri
    Organizer: Ben May Center for Chemical Theory and Computation
    Contact: eli.pollak@weizmann.ac.il
    Abstract: The interplay among electronic coherence, vibrational damping, quantum dispersio ... Read more The interplay among electronic coherence, vibrational damping, quantum dispersion, topological effects and thermal fluctuations leads to rich behaviors in the dynamics of excitation energy flow. We use real-time path integral methods developed in our group to perform fully quantum mechanical simulations of excitation energy transfer in large molecular aggregates. The systems are described through a Frenkel exciton Hamiltonian where all vibrational normal modes of each molecular unit and their coupling to the ground and excited electronic states are treated explicitly at any temperature. Simulations have been carried out in J aggregates of perylene bisimide, model dendrimers, and photosynthetic light harvesting complexes. Coherence maps offer powerful visualization tools that reveal the creation and destruction of quantum superpositions and enable a state-to-state pathway analysis of energy flow.
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    Ben May Lecture series

    Date:
    03
    Tuesday
    January
    2023
    Lecture / Seminar
    Time: 11:00
    Title: The Second Kind of Impossible: The Extraordinary Search for Natural Quasicrystals
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Paul Steinhardt
    Organizer: Ben May Center for Chemical Theory and Computation
    Contact: eran.bouchbinder@weizmann.ac.il
    Abstract: Quasicrystals are exotic materials that have symmetries that once thought to be ... Read more Quasicrystals are exotic materials that have symmetries that once thought to be impossible for matter. The first known examples were synthesized in the laboratory 30 years ago, but could Nature have beaten us to the punch? This talk will describe the decades-long search to answer this question, resulting in one of the strangest scientific stories you are ever likely to hear.
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