Tags: Physical Seminar

Weak magnetic fields (< 30 mT) can have a profound influence on radical pair reactions. This is, at first sight, puzzling since the magnetic interactions are typically much smaller than the thermal energy at room temperature. The radical pair is created in a highly non-equilibrium state, however, displaying significant mixing between its singlet and triplet spin states. The mixing rate is altered if a magnetic field is present via the Zeeman…
Chemical applications of statistical mechanics typically assume that the electronic partition function is trivial, as all members of the system are in the ground electronic state. When this approximation breaks down (example: electrical conductors), it is necessary to combine statistical mechanics and electronic structure theory to determine the electronic partition function. This composite theory is called a "finite-temperature" theory. The…
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…