Comprehensive theoretical study of the correlation between the energetic and thermal stabilities for the entire set of 1812 C60 isomers

Abstract

<p>The thermal stability of fullerenes plays a fundamental role in their synthesis and in their thermodynamic and kinetic properties. Here, we perform extensive molecular dynamics (MD) simulations using an accurate machine-learning-based Gaussian Approximation Potential (GAP-20) force field to investigate the energetic and thermal properties of the entire set of 1812 C₆₀ isomers. Our MD simulations predict a comprehensive and quantitative correlation between the relative isomerization energy distribution of the C₆₀ isomers and their thermal fragmentation temperatures. We find that the 1812 C₆₀ isomers span over an energetic range of over 400 kcal mol^-1, where the majority of isomers (~85%) lie in the range between 90 and 210 kcal mol^-1 above the most stable C₆₀-<i>I</i>_h buckminsterfullerene. Notably, the MD simulations show a clear statistical correlation between the relative energies of the C₆₀ isomers and their fragmentation temperature. The maximum fragmentation temperature is 4800 K for the C₆₀-<i>I</i>_h isomer and 3700 K for the energetically least stable isomer, where nearly 80% of isomers lie in a temperature window of 4000–4500 K. In addition, an Arrhenius-based approach is used to map the timescale gap between simulation and experiment and establish a connection between the MD simulations and fragmentation temperatures.</p>