Relation between occupation in the first coordination shells and Widom line in Core-Softened Potentials

Abstract

Three core-softened families of potentials are checked for the presence of density and diffusion anomalies. These potentials exhibit a repulsive core with a softening region and at larger distances an attractive well. We found that the region in the pressure-temperature phase diagram in which the anomalies are present increases if the slope between the core-softened scale and the attractive part of the potential decreases. The anomalous region also increases if the range of the core-softened or of the attractive part of the potential decreases. We also show that the presence of the density anomaly is consistent with the non monotonic changes of the radial distribution function at each one of the two scales when temperature and density are varied. Then, using this anomalous behavior of the structure we show that the pressures and the temperatures in which the radial distribution functions of the two length scales are equal are identified with the Widom line.

References in corpus (8)

• Excess entropy, Diffusivity and Structural Order in liquids with water-like anomalies
• Water-like hierarchy of anomalies in a continuous spherical shouldered potential
• Quasi-binary amorphous phase in a 3D system of particles with repulsive-shoulder interactions
• Structural anomalies for a three dimensional isotropic core-softened potential
• Phase behaviour of attractive and repulsive ramp fluids: integral equation and computer simulation studies
• Interplay between structure and density anomaly for an isotropic core-softened ramp-like potential
• Core-softened Fluids, Water-like Anomalies and the Liquid-Liquid Critical Points
• Thermodynamic, Dynamic, Structural and Excess Entropy Anomalies for core-softened potentials

Cited by in corpus (4)

• Waterlike anomalies in hard core-soft shell nanoparticles using a effective potential approach: pinned vs adsorbed polymers
• Core-softened water-alcohol mixtures: the solute-size effects
• Competing interactions near the liquid-liquid phase transition of core-softened water/methanol mixtures
• Single-file mobility of water-like fluid in a generalized Frenkel-Kontorova model