Condensed Matter Physics, 2017, vol. 20, No. 4, 43301
DOI:10.5488/CMP.20.43301           arXiv:1712.05326

Title: Modelling of potentials for interparticle interactions between methanol molecules
Author(s):
  N.P. Malomuzh (Odesa I.I. Mechnikov National University, 2 Dvoryansíka St., 65026 Odesa, Ukraine) ,
  M.V. Timofeev (Odesa I.I. Mechnikov National University, 2 Dvoryansíka St., 65026 Odesa, Ukraine)

Peculiarities of interparticle interactions between methanol molecules in the methanol vapor are investigated. The bare potential is considered as a sum of repulsive, dispersive and electrostatic forces. It is supposed that H-bond is of electrostatic nature (the irreducible contribution caused by overlapping of electronic shells is unessential). The dispersive interaction is approximated with Londonís formula, the electrostatic interaction is modelled by a multipole expansion up to dipole-octupole contribution. The multipole moments are assumed to be equal to their experimental values or to quantum chemical calculations. The repulsion is modelled by power potential, whose parameters are fitted to the second virial coefficient and to the parameters of dimers. Along with the bare potential, the averaged potential of interparticle interaction is analyzed. It is shown that the repulsive potential has an exponent n=28. The multipole potential, presented in this paper, is scrupulously compared with the potential known as the OPLS.

Key words: methanol, interaction potential
PACS: 34.20.Gj, 51.30.+i


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