Statistical Thermodynamics & Molecular Simulations (STMS) Seminar Series
These seminar series are aimed at providing a virtual platform for sharing scientific research in the area of statistical mechanics, molecular simulations, and computational materials science. In recent months, the coronavirus pandemic has stopped all large in-person scientific gatherings, including conferences and department seminars, and it is not clear that the situation will improve any time soon. STMS is aimed at filling this gap, and provide a venue for dissemination of research findings and exchange of ideas in the age of COVID. This model is being currently used by several other scientific communities, and can potentially continue even beyond the pandemic if successful. Each seminar will be a 60-minute event and will comprise of a long-form (30-minute) talk by a principal investigator or a senior research scientists from academia or industry and a short-form (15-minute) presentation by a graduate student or a postdoc. The remainder of the event will be dedicated to Q&A (10 minutes for the PI, 5 minutes for the student/postdoc). Long-form speakers will be chosen by the STMS Organizing Committee, while we encourage suggestions from the community at large. Student and postdoctoral speakers, however, need to be nominated by their advisors. Seminars will take place on Fridays, from 11 AM-12 PM. During 2021, we will have two events per month taking place in the last two Fridays of each month.
This event's talks:
The phase behavior of supercooled water: Recent computational results
Prof. Pablo G. Debenedetti (Department of Chemical and Biological Engineering, Princeton University)
Abstract: Water plays a central role in the physical and chemical processes that sustain life as we know it. Its ubiquity and importance notwithstanding, there remain major open questions concerning water’s physical properties, which are anomalous by comparison to those of most other liquids. Water’s oddities become more pronounced at low temperatures, especially in the supercooled regime, where the liquid is metastable with respect to crystallization. The existence of a phase transition between two liquid forms of water, terminating at a critical point under deeply supercooled conditions, has been proposed as a thermodynamically consistent way of interpreting experimental observations. I will present recent computational results on metastable criticality in realistic models of water (Debenedetti et al., Science, 369, 289, 2020), probing supercooled water thermodynamics with an ab-initio deep neural network model (Gartner et al., PNAS, 117, 26040, 2020), and the relationship between the long-range structure of water glasses and criticality (Gartner et al., 2021).
Bio: Pablo Debenedetti is the Class of 1950 Professor in Engineering and Applied Science, Professor of Chemical and Biological Engineering, and Dean for Research at Princeton University, whose faculty he joined in 1985. He received his undergraduate and graduate degrees in Chemical Engineering at the University of Buenos Aires (1978) and at the Massachusetts Institute of Technology (MSc 1981, PhD 1984), respectively. His research interests include the thermodynamics and statistical mechanics of liquids and glasses; water and aqueous solutions; protein thermodynamics; nucleation; metastability; and the origin of biological homochirality. He is the author of one book, Metastable Liquids, and more than 300 scientific articles. His accomplishments include proving the existence of a metastable liquid-liquid transition in a molecular model of water, performing the first direct calculation of homogenous ice nucleation rates in a realistic model of water, and uncovering the relationships between liquid dynamics and exploration of the energy landscape, and between structural order and the anomalies of liquid water. Debenedetti’s honors include the NSF’s Presidential Young Investigator Award (1987); the Camille and Henry Dreyfus Teacher-Scholar Award (1989); a Guggenheim Memorial Foundation Fellowship (1991); the Professional Progress (1997), Walker (2008), Institute Lecture (2013) and Alpha Chi Sigma (2019) awards from the AIChE; the J. M. Prausnitz Award in Applied Chemical Thermodynamics (2001); the Hildebrand Award in the Theoretical and Experimental Chemistry of Liquids from the ACS (2008); and the Guggenheim Medal from the Institution of Chemical Engineers (2017). He received the President’s Award for Distinguished Teaching (2008), Princeton’s highest distinction for teaching. In 2008 Debenedetti was named one of 100 Chemical Engineers of the Modern Era by the AIChE. He is a member of the National Academy of Engineering, the American Academy of Arts and Sciences, and the National Academy of Sciences, and a fellow of AAAS, AIChE and APS.
On the relationship between structure and dynamics in liquid water
Ezekiel Piskulich (Department of Chemistry, University of Kansas)
Abstract: The close relationship between the dynamics of liquids and their underlying structure has long been of interest. We examine this connection by applying the recently developed fluctuation theory for dynamics [Z.A. Piskulich, O.O. Mesele, and W.H. Thompson, “Activation Energies and Beyond,” J. Phys. Chem. A. 123, 7185 (2019).] to calculate the underlying temperature dependence of both the diffusion coefficient and radial distribution function of water under ambient conditions. Specifically, we use the fluctuation theory approach to calculate the diffusion activation energy from simulations at a single temperature and illustrate that it is quantitatively determined by the enthalpic barriers, obtained from the oxygen-oxygen radial distribution function, for waters to move between solvation shells. We then demonstrate that these correlations can be used to infer the experimental hydrogen-bond exchange time activation energy.
Bio: Zeke Piskulich is currently a NSF graduate research fellow working with Brian Laird and Ward Thompson at the University of Kansas in the Department of Chemistry. He received his B.S. in Physics at the University of Missouri in 2017, where he worked with Thomas Sewell and Donald Thompson. During his Ph.D. work, he has been developing the fluctuation theory for dynamics, a technique for evaluating temperature and pressure derivatives of dynamical timescales (e.g., diffusion coefficients) from molecular dynamics simulations at a single temperature and pressure.