<h3>Title</h3>
<p><span style="color: #0000ff;">Exact Quantum Dynamics of Open Systems</span></p>
<p><strong><span style="text-decoration: underline;">Abstract</span> :</strong></p>
<p style="text-align: justify;">An ability to accurately simulate the dynamics of quantum systems is essential to understanding all of Chemistry and much of Physics.  While quantum mechanics is, in principle, linear in time, simulations scale exponentially with degrees of freedom.  This is a huge problem when it comes to simulating large systems involving quantum transport.  Broadly, computational approaches can be classified as ones based on “augmented” classical trajectories and ones that are based on a “system-solvent decomposition.” In this first presentation, I would discuss the work that I have done on path integral methodologies for simulating system-solvent dynamics.  This technique of decomposing the problem into a system, treated at a more accurate level of theory, and a solvent, that is typically traced over, is particularly effective if the quantum effects are limited to a small subspace of the problem.  While various formalisms exist to simulate a system-solvent problem, they are typically plagued by computational bottlenecks.  Methods of speeding up such simulations<sup>1, 2</sup> would be presented.  Recently, I have developed an exciting simulation framework combining various tensor network approaches with Feynman-Vernon influence functionals<sup>3-5</sup>.  The most exciting method in this family combines ideas from density matrix renormalization group (DMRG) with influence functionals to give rise to a very promising framework that even in its most primitive form is able to solve problems involving dissipative molecular aggregates and spin chains with unprecedented efficiency.  I would discuss these developments, illustrating their wide-ranging applicability through simulations of essentially quantum mechanical, non-adiabatic processes like electron<sup>4</sup> and excitonic energy<sup>6</sup> transfer.  Recent results exploring energy transfer in photosynthetic complexes along with the effect of local vibrations and spatial inhomogeneities will also be shown.</p>
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<h1>References</h1>
<ol>
<li>Bose, A.; Makri, N., Non-equilibrium reactive flux: A unified framework for slow and fast reaction kinetics. <em>J. Chem. Phys. </em><strong>2017,</strong> <em>147</em> (15), 152723.</li>
<li>Bose, A.; Makri, N., Quantum‐classical path integral evaluation of reaction rates with a near‐equilibrium flux formulation. <em>Int. J. Quantum Chem. </em><strong>2021,</strong> <em>121</em> (10).</li>
<li>Bose, A., A Pairwise Connected Tensor Network Representation of Path Integrals. <em>arXiv pre-print server </em><strong>2021</strong>.</li>
<li>Bose, A.; Walters, P. L., A tensor network representation of path integrals: Implementation and analysis. <em>arXiv pre-print server </em><strong>2021</strong>.</li>
<li>Bose, A.; Walters, P. L., A Multisite Decomposition of the Tensor Network Path Integrals. <em>arXiv pre-print server </em><strong>2021</strong>.</li>
<li>Bose, A.; Makri, N., All-Mode Quantum–Classical Path Integral Simulation of Bacteriochlorophyll Dimer Exciton-Vibration Dynamics. <em>J. Phys. Chem. B </em><strong>2020,</strong> <em>124</em> (24), 5028-5038.</li>
</ol>