Ordering of Soft Regular Polygons in Two-Dimensions

Abstract

Studies of phase transitions in two-dimensional (2D) system is a fundamental, long-standing problem in statistical mechanics and have an interesting melting phenomenon. It was observed that the 2D solid melted through three scenarios, depending upon both particle shape and symmetry. We investigate the phase behavior of regular soft polygons with the N number of the subatomic particle ($ 2 \leq N \leq 5 $) in 2D. By studying these types of molecules, we show that the phase behavior depends upon both enthalpic and configuration entropy. For this, we study the phase behavior of a soft regular polygon under two types of interaction, Lennard-Jone potential (attractive) and Yukawa potential (repulsive), with different values of N. Our results show that the enthalpic entropy has a more significant effect on phase transition than configurational entropy. We present the results from the LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) simulation of a rigid body system under the influence of enthalpic and configurational entropy varied one by one. As a result, phase transitions are studied as a function of temperature and the number density of the system. We have used various investigating techniques such as tracking particle positions, radial distribution function, and statistical structure factor to identify the phases. We show the effect of enthalpic and configurational entropy on the phases of the system. Hence, we obtained a phase diagram of soft-regular-polygonal material under different conditions.