Title: On the thermodynamic properties of the generalized Gaussian core model
Authors: B.M.Mladek (Center for Computational Materials Science and Institut für Theoretische Physik, Technische Universität Wien, Wiedner Hauptstraße 8-10, A-1040 Wien, Austria; Institut für Experimentalphysik, Universität Wien, Strudlhofgasse 4, A-1090 Wien, Austria) , M.J.Fernaud, G.Kahl (Center for Computational Materials Science and Institut für Theoretische Physik, Technische Universität Wien, Wiedner Hauptstraße 8-10, A-1040 Wien, Austria) , M.Neumann (Institut für Experimentalphysik, Universität Wien, Strudlhofgasse 4, A-1090 Wien, Austria)

We present results of a systematic investigation of the properties of the generalized Gaussian core model of index n. The potential of this system interpolates via the index n between the potential of the Gaussian core model and the penetrable sphere system, thereby varying the steepness of the repulsion. We have used both conventional and self-consistent liquid state theories to calculate the structural and thermodynamic properties of the system; reference data are provided by computer simulations. The results indicate that the concept of self-consistency becomes indispensable to guarantee excellent agreement with simulation data; in particular, structural consistency (in our approach taken into account via the zero separation theorem) is obviously a very important requirement. Simulation results for the dimensionless equation of state, β P / ρ, indicate that for an index-value of 4, a clustering transition, possibly into a structurally ordered phase might set in as the system is compressed.

Key words: soft matter, integral equations, computer simulations, clustering transition, Gaussian core model
PACS: 61.20.Gy, 61.20.Ja, 64.10.+h