Beyond Arrhenius: Fluctuation Theory for Dynamics

POSTER

Abstract

Often the local temperature-dependence of dynamical timescales is evaluated by calculating activation energies using an Arrhenius approach to evaluate the numerical temperature derivative of the dynamical timescale. This numerical approach can fail however when the timescales are non-Arrhenius, or when the system undergoes conformational or compositional changes with temperature. To circumvent these problems, we have developed a fluctuation theory approach for dynamics  [Z.A. Piskulich, O.O. Mesele, and W.H. Thompson, “Activation Energies and Beyond,” J. Phys. Chem. A. 123, 7185 (2019).] that allows for derivatives of dynamical timescales to be evaluated from simulations at a single temperature. Presently, we use this fluctuation theory approach to calculate derivatives of the diffusion coefficient in liquid water under ambient conditions and demonstrate that they can be used to predict the temperature-dependence of the diffusion coefficient in the supercooled regime of water. We then demonstrate that fluctuation theory applied to water’s liquid structure can be used to calculate the enthalpy change associated with hydrogen bond exchanges, and that this quantity is closely linked to the activation energy. 

Publication: [1] Zeke A. Piskulich, Oluwaseun O. Mesele, and Ward H. Thompson. Removing the barrier to the calculation of activation energies: Diffusion coefficients and reorientation times in liquid water. J. Chem. Phys., 147(13):134103, 2017.
[2] Zeke A. Piskulich, Oluwaseun O. Mesele, and Ward H. Thompson. Expanding the calculation of activation volumes: Self-diffusion in liquid water. J. Chem. Phys., 148(13):134105, 2018.
[3] Zeke A. Piskulich and Ward H. Thompson. The activation energy for water reorientation differs between IR pump-probe and NMR measurements. J. Chem. Phys., 149(16):164504, 2018.
[4] C.H. Mendis, Zeke A. Piskulich, and Ward H. Thompson. Tests of the Stokes-Einstein Relation through the Shear Viscosity Activation Energy of Water. J. Phys. Chem. B., 123:5857–5865, 2019.
[5] Zeke A. Piskulich, Oluwaseun O. Mesele, and Ward H. Thompson. Activation Energies and Beyond. J. Phys. Chem. A., 123:7185–7194, 2019.
[6] Ashley K. Borkowski, Zeke A. Piskulich, and Ward H. Thompson. Examining the Hofmeister Series through Activation Energies: Water Diffusion in Aqueous Alkali-Halide Solutions. The Journal of Physical Chemistry B, 125:350–359, 2020.
[7] Zeke A Piskulich and Ward H Thompson. Temperature Dependence of the Water Infrared Spectrum: Driving Forces, Isosbestic Points, and Predictions. J. Phys. Chem. Lett., 11:7762–7768, 2020.
[8] Zeke A. Piskulich, Damien Laage, and Ward H Thompson. Activation energies and the extended jump model : How temperature affects reorientation and hydrogen-bond exchange dynamics in wa- ter Activation energies and the extended jump model : How temperature affects reorientation and hydrogen-bond exchange dynamic. J. Chem. Phys., 153:074110, 2020.
[9] Zeke A. Piskulich and Ward H Thompson. The dynamics of supercooled water can be predicted from room temperature simulations The dynamics of supercooled water can be predicted from room temperature simulations. J. Chem. Phys., 152:074505, 2020.
[10] Zeke A. Piskulich and Ward H. Thompson. On the temperature dependence of liquid structure. J. Chem. Phys., 152:011102, 2020.
[11] Zeke A. Piskulich, Damien Laage, and Ward H. Thompson. On the role of hydrogen bond exchanges in the spectral diffusion of water. J. Chem. Phys., 154:064501, 2021.
[12] Zeke A. Piskulich and Ward H. Thompson. Examining the Role of Different Molecular Interactions on Activation Energies and Activation Volumes in Liquid Water. J. Chem. Theor. Comput., 17(5): 2659–2671, 2021.
[13] Zeke A Piskulich and Brian B Laird. Molecular Simulations of Phase Equilibria and Transport Properties in a Model CO 2 - Expanded Lithium Perchlorate Electrolyte. J. Phys. Chem. B, 125: 9341–9349, 2021.
[14] Zeke A. Piskulich, Damien Laage, and Ward H. Thompson. Using Activation Energies to Elucidate Mechanisms of Water Dynamics. Submitted., 2021.

Presenters

  • Zeke A Piskulich

    Boston University

Authors

  • Zeke A Piskulich

    Boston University