Liquid state dynamics play a key role in most biological reactions, and many other processes central to technology and life. In spite of this, there is still no simple theory of liquid state dynamics and thermodynamics. However, there are exciting new developments suggesting that understanding motions in these condensed amorphous systems that occur on a molecular lengthscale and picosecond timescale may lead to a simplified and possibly comprehensive model of these important systems. Our work is focused on developing a detailed understanding the complex relationship between fundamental, picosecond timescale, relaxation processes in liquids and the menagerie of longer timescale types of relaxation that result from them. The work has many important technological implications as these longer timescale processes include diffusion, viscous flow, and ionic conductivity.
Cicerone, M. T., Zhong, Q. & Tyagi, M. Picosecond Dynamic Heterogeneity, Hopping, and Johari-Goldstein Relaxation in Glass-Forming Liquids. Phys. Rev. Lett. 113, 117801 (2014).
Cicerone, M. T. & Tyagi, M. Metabasin transitions are Johari-Goldstein relaxation events. The Journal of Chemical Physics 146, (2017).