Tags: Physical Seminar

Analysis of various studies conducted using shock tubes in order to determine products, mechanisms, as well as rate coefficients and kinetics. The use of shock tubes allow for highly reproducible and precise studies of high-temperature environments and allow for the study of the products and reactions caused with the introduction of these extreme conditions.  
Abstract: Monte Carlo methods have been used in quantum chemistry for decades to obtain high-accuracy solutions to the electronic Schrodinger equation. These stochastic methods are useful due to their arbitrary accuracy and ease of implementation compared to deterministic methods. The recently-developed full configuration interaction quantum Monte Carlo (FCIQMC) method [Nature, 2013, 493 (7432), 365–370] is perhaps the most promising of these…
Since their development in the 1960s, lasers have been used in a myriad of ways to study and influence chemical reactions. In this talk, three topics will be addressed: photodissociation, metallized polymers, and large-cluster reactivity. The role of the laser in probing and altering reaction timescales will be examined.
  Dynamical resonances are quasi-bound quantum states that exist in the vicinity of a transition state for a bimolecular reaction.  These resonances are predicted to be ubiquitous among chemical reactions and can mediate reactivity at low temperatures. However, only a handful of resonances have been definitively observed or characterized.  Slow photoelectron velocity-map imaging of cryogenically cooled anions (cryo-SEVI) is a…
  Abstract: Fragment embedding divides the description of a system into smaller and more cost-friendly pieces for computation. For systems with strong correlation, the challenge is to properly describe the entanglement effect of the environment on the embedded fragment. The recently developed Bootstrap Embedding [JCTC, 15, 4497 (2019)] uses overlapping fragments to improve fragment description at the edges,  and will be reviewed in…
Automatic Differentiation (AD) is a general method for obtaining derivatives of arbitrarily complex functions in computer programs. Naturally, such a tool would seem invaluable to computational chemistry applications. Some current developments and limitations of applying AD to quantum chemistry techniques presented in the literature are discussed.