Reentrant and Isostructural Transitions in a Cluster-Crystal Former

TL;DR

This paper investigates the complex phase behavior of a cluster-crystal forming system, revealing reentrant transitions, isostructural phase changes, and unusual softening phenomena through simulation.

Contribution

It introduces the first detailed simulation study of reentrant and isostructural transitions in a cluster-crystal system, highlighting unique softening behavior.

Findings

Reentrant crystallization and melting loops observed.

Critical isostructural transitions between different crystal occupancies.

Unusual softening upon compression due to lattice site dynamics.

Abstract

We study the low-temperature behavior of a simple cluster-crystal forming system through simulation. The phase behavior is found to be hybrid between the Gaussian core and penetrable sphere models. The system additionally exhibits a series of reentrant crystallization and melting loops as well as critical isostructural transitions between crystals of different occupancy. Due to the creation and annihilation of lattice sites, the system further shows an unusual and intriguing softening upon compression.