Measuring pressure in equilibrium and nonequilibrium lattice-gas models

Area of Science:

• Statistical Mechanics
• Computational Physics

Background:

• Lattice-gas models are fundamental in statistical mechanics for studying phase transitions and fluid behavior.
• Directly measuring pressure in these models can be computationally intensive, especially for complex systems.

Purpose of the Study:

• To introduce a novel, efficient algorithm for direct pressure measurement in lattice-gas models.
• To enable accurate equation of state calculations with improved computational efficiency.

Main Methods:

• Algorithm development based on Dickman's method.
• Incorporation of multiple ghost sites into the original lattice-gas system.
• Application to various paradigmatic systems including lattice gas under gravity and exclusion processes.

Main Results:

• The algorithm allows for equation of state determination in a single computational run.
• Demonstrated efficiency for systems with inhomogeneous density profiles (equilibrium and nonequilibrium).
• Successful application to diverse models like lattice gas under gravity and exclusion processes on different graph structures.

Conclusions:

• The developed algorithm offers a significant computational advantage for pressure measurement in lattice-gas models.
• Its versatility makes it suitable for a wide range of statistical mechanics systems.
• Provides a powerful tool for studying systems with complex density distributions.