6533b820fe1ef96bd1279b90

RESEARCH PRODUCT

Simulation studies of gas-liquid transitions in two dimensions via a subsystem-block-density distribution analysis

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The finite-size scaling analysis of the density distribution function of subsystems of a system studied at constant total density is studied by a comparative investigation of two models: (i) the nearest-neighbor lattice gas model on the square lattice, choosing a total lattice size of 64×64 sites. (ii) The two-dimensional off-lattice Lennard-Jones system (truncated at a distance of 2.5 σ, σ being the range parameter of the interaction) withN=4096 particles, applying the NVT ensemble. In both models, the density distribution functionPL(ρ) is obtained forL×L subsystems for a wide range of temperaturesT, subblock linear dimensionsL and average densities . Particular attention is paid to the question whether accurate estimates of critical temperatureTc and critical density ρc can be obtained. In the lattice gas model these critical parameters are known exactly and the limitations of the approach can thus be definitively asserted. The final estimates for the Lennard Jones problem areTc=0.47±0.01 (in units of the Lennard Jones energy e) and ρc (in units of σ2), a comparison with previous estimates is made.