Speaker
Thomas Schrøder
(Dept. of Sciences, Roskilde University, Roskilde, Denmark)
Description
The original formulation of the Isomorph Theory [1] predicts
that some liquids have "isomorphs", i,e,, lines of invariant
dynamics, structure and excess entropy in parts of their
phase diagram, Here we present a new - and more elegant -
version of the theory, which from a single assumption
regarding the scaling properties of the high-dimensional
potential energy surface predicts the existence of isomorphs
[2]. Furthermore, the new version of the theory solves some
of the (few) problems of the original version, e.g., the
variance of heat capacity along an isomorph is now
accurately predicted. Finally, we will discuss the extension
to "pseudoisomorphs" in liquids with intramolecular
vibrational degrees of freedom [3].
[1] N. Gnan, T.B. Schrøder, U.R. Pedersen, N.P. Bailey, and
J.C. Dyre, "Pressure-energy correlations in liquids. IV.
'Isomorphs' in liquid state diagrams", Journal of Chemical
Physics v131, p234504 (2009)
[2] T.B. Schrøder and J.C. Dyre, "Simplicity of condensed
matter at its core: Generic definition of a Roskilde-simple
system", Journal of Chemical Physics, v141, p204502 (2014).
[3] A.E. Olsen, J.C. Dyre, and T.B. Schrøder,
"Communication: Pseudoisomorphs in liquids with
intramolecular degrees of freedom", Journal of Chemical
Physics, v145, p241103 (2016).
