Extensions of the interfacial pinning method and application to hard core systems

Area of Science:

• Condensed matter physics
• Thermodynamics
• Computational chemistry

Background:

• Accurate estimation of phase transition locations is crucial for understanding condensed matter systems.
• The interface pinning (IP) technique offers a precise method for fluid-solid transitions in single-component systems using the NP(z)T ensemble.
• Existing methods may have limitations in applicability to diverse systems and ensembles.

Purpose of the Study:

• To extend the interface pinning (IP) method for phase transition estimation to various thermodynamic ensembles.
• To adapt the IP method for both single-component systems and binary mixtures.
• To develop a generalized extrapolation scheme for properties at coexistence conditions.

Main Methods:

• Extension of the interface pinning (IP) technique to multiple ensembles (e.g., NVT, NPT).
• Application of IP to binary mixtures, including hard cubes and spheres.
• Development of a general extrapolation framework for coexistence properties.
• Investigation of different order parameters, including volume, for phase identification.

Main Results:

• The IP method was successfully extended to different ensembles and applied to binary mixtures.
• Coexistence pressure for isotropic-rotator transitions in polyhedral systems was estimated.
• Isotropic-crystal coexistence compositions for binary hard cubes and spheres were determined.
• Volume was identified as a viable, often more practical, order parameter than translational order parameters.

Conclusions:

• The generalized interface pinning (IP) framework enhances the accurate prediction of phase transitions across diverse systems and conditions.
• The study validates the utility of volume as an order parameter, offering a computationally efficient alternative.
• This work provides a robust computational tool for studying phase equilibria in complex materials.