Excitations follow (or lead?) density scaling in propylene carbonate
Abstract
Structural excitations that enable interbasin (IB) barrier crossings on a potential energy landscape are thought to play a facilitating role in the relaxation of liquids. Here, we show that the population of these excitations exhibits the same density scaling observed for α relaxation in propylene carbonate, even though they are heavily influenced by intramolecular modes. We also find that IB crossing modes exhibit a Grüneisen parameter (γG) that is approximately equivalent to the density scaling parameter γTS. These observations suggest that the well-documented relationship between γG and γTS may be a direct result of the pressure dependence of the frequency of unstable (relaxation) modes associated with IB motion.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 28, 2022
- Source ID
- 10.1063/5.0123444
Entities
People
- Jesse McDaniel
- John P. Stoppelman
- Marcus T Cicerone
Organizations
- Air Force Office of Scientific Research
- Georgia Tech