Thermal expansion coefficient in simple models of condensed matter

Thermal expansion coefficient behavior is compared for simple models of condensed matter (unimodal and bimodal systems of hard spheres and disks) and different pair interaction potentials (Lennard-Jones particle systems). The role of different nonlinear effects, determined by these potentials' specialty, is estimated. The analysis is based on previously suggested molecular-dynamic model of the condensed state. The qualitative difference of thermal expansion coefficient's temperature dependence for the systems with hard spheres-type and Lennard-Jones potential is revealed. That is accented, since the dependence of other thermodynamic characteristics (heat capacity, mechanical properties) on the model potential is much weaker.