Keynote Talk III

Eva Zurek
21 Jul 2017
11:00 -12:00
Burgiss Theatre

Keynote Talk III

Chemistry Under Pressure

The pressure variable opens the door towards the synthesis of materials with unique properties, i.e. superconductivity, hydrogen storage media, high-energy density and superhard materials, to name a few. Indeed, recently superconductivity has been observed below 203 K and 103 K in samples of compressed sulfur dihydride and phosphine, respectively. Under pressure elements that would not normally combine may form stable compounds, or may mix in novel proportions. As a result, using our chemical intuition developed at 1 atmosphere to theoretically predict stable phases is bound to fail. In order to enable our search for superconducting hydrogen-rich systems under pressure, we have developed XtalOpt, an open-source evolutionary algorithm for crystal structure prediction. XtalOpt has been employed to find the most stable structures of hydrides with unique stoichiometries under pressure. The electronic structure and bonding of the predicted phases has been analyzed by detailed first-principles calculations based on density functional theory. The results of our computational experiments are helping us to build chemical and physical intuition for compressed solids.

Recommended Readings:

Superconductivity in Hydrides Doped with Main Group Elements Under Pressure
Andrew Shamp and Eva Zurek
Nov. Supercond. Mater. 2017; 3:14–22

Superconducting High-Pressure Phases Composed of Hydrogen and Iodine
Andrew Shamp and Eva Zurek
J. Phys. Chem. Lett. 2015, 6, 4067−4072

XtalOpt: An open-source evolutionary algorithm for crystal structure prediction
David C. Lonie, Eva Zurek∗
Computer Physics Communications 182 (2011) 372–387

Decomposition Products of Phosphine Under Pressure: PH2 Stable and Superconducting?
Andrew Shamp, Tyson Terpstra, Tiange Bi, Zackary Falls, Patrick Avery, and Eva Zurek
J. Am. Chem. Soc. 2016, 138, 1884−1892

Discovering New Materials via a priori Crystal Structure Prediction
Eva Zurek

Predicting crystal structures and properties of matter under extreme conditions via quantum mechanics: the pressure is on
Eva Zurek and Wojciech Grochala
Phys. Chem. Chem. Phys., 2015, 17, 2917–2934

A pressing matter
Russell J Hemley
Physics World August 2006

The Squeeze Is On
Roald Hoffmann
The American Scientist.org. March-April 2009