Events & Seminars > Event Details

Where:

4:00 pm
Room 304, Chemistry Building

Investigating mysteries of water from first principles

Speaker:

Professor Krzystof Szalewicz
University of Delaware

Hosted by: Professor Kevin Lehmann

Water is a substance of uttermost importance and has many anomalous properties, poorly understood at the molecular level. Since the water molecule is a relatively simple one, there is hope that rst-principles (ab initio) theory can provide deeper insights into such properties. All theoretical investigations of water, from water clusters to condensed phases, require knowledge of an intermolecular potential energy surface describing interactions between water molecules. Such surfaces date back to the 1940s, but until recently a given surface was capable to describe well only some speci c forms of water. In 2007, our group developed the rst potential of this type that was universal, i.e., described well all forms of water from the water dimer to condensed phases [1]. It was developed entirely from rst principles, i.e., without using any information from experiments. Since that time, still more accurate potentials have been published [2, 3] and applied to compute, among others, (a) water dimer spectra including infra-red shifts that challenge experiments; (b) energetics of water clusters which is as accurate as that from the most sophisticated calculations at single cluster’s geometries; (c) the radial oxygen-oxygen distribution function for liquid water which agrees with a recent experiment better than analogous functions from empirical models tted to experimental data. Work in progress includes both investigation of the mysterious properties of water such as the liquid water density maximum and applications of industrial importance such as creation of a benchmark virial coecient function.
[1] R. Bukowski, K. Szalewicz, G. C. Groenenboom, and A. van der Avoird, Science 315, 1249 (2007).
[2] U. Gora, W. Cencek, R. Podeszwa, A. van der Avoird, and K. Szalewicz, J. Chem. Phys. 140, 194101 (2014).
[3] P. Jankowski, G. Murdachaew, R. Bukowski, O. Akin-Ojo, C. Leforestier, and K. Szalewicz, J. Phys. Chem. A 119, 2940 (2015).

 

Krzysztof Szalewicz is a Professor of Physics and Chemistry at the University of Delaware. He obtained his Ph.D.
in 1977 and his D.Sc. in 1984, both from the University of Warsaw. Before coming to Delaware in 1988, he held
faculty positions at the University of Warsaw and at the University of Florida. His visiting appointments were
at the universities of Uppsala, Colorado (JILA), Harvard, Princeton, and Grenoble. His expertise is in theory of
intermolecular forces and in theory of electron correlation. He pioneered symmetry-adapted perturbation theory
(SAPT) which became one of the main methods of investigating intermolecular forces. Among the approaches that
are capable of calculating highly accurate interaction energies, including dispersion contributions, SAPT based on
density-functional theory is currently the only one that can be applied to systems with hundreds atoms. His group
wrote and maintains a system of codes performing calculations of two- and three-body intermolecular interaction
energies using SAPT. The force elds developed by his group enable accurate predictions of spectra of van der Waals
clusters, properties of liquids, and of structure of molecular crystals. Krzysztof Szalewicz is an elected member of
the International Academy of Quantum Molecular Science and of the Committee on Arts and Science of the Franklin
Institute. He has published more than 230 papers with h-index of 57.