Concerning a Calculation of the Grand Partition Function of a Fluid Model

  • M. P. Kozlovskii Institute for Condensed Matter Physics, Nat. Acad. of Sci. of Ukraine
  • O. A. Dobush Institute for Condensed Matter Physics, Nat. Acad. of Sci. of Ukraine
  • R. V. Romanik Institute for Condensed Matter Physics, Nat. Acad. of Sci. of Ukraine
Keywords: coexistence curve, collective variables, reference system, simple fluid, equation of state


The calculation method of the grand partition function of a simple fluid model in the frame of a generalized lattice model, where each cell may contain a random number of particles, is proposed. As an interaction potential between particles, the Morse potential is chosen. In vcourse of calculations, the summation over the number of particles and the integration over their coordinates are performed. Using the simplest approximation, the equation of state valid in a wide temperature range is obtained. At temperatures lower than the critical one, the presence of horizontal plots on the pressure vs density curve is found.


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How to Cite
Kozlovskii, M., Dobush, O., & Romanik, R. (2019). Concerning a Calculation of the Grand Partition Function of a Fluid Model. Ukrainian Journal of Physics, 60(8), 805.
General problems of theoretical physics