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Evaluation of second and third dielectric virial coefficients for non-polarisable molecular models.
- Source :
-
Molecular Physics . Apr2017, Vol. 115 Issue 8, p991-1003. 13p. - Publication Year :
- 2017
-
Abstract
- The dielectric constant, ε, of a dilute vapour can be estimated from the dielectric virial equation of state (VEOS), but the long-ranged nature of the electrostatic interactions complicates the evaluation of coefficients of this series. We propose a formulation of the second and third dielectric coefficients of a general non-polarisable molecular model that permits their reliable calculation using Mayer sampling Monte Carlo. We demonstrate for three models: dipolar hard spheres, dipolar Lennard–Jones, and TIP4P water. The coefficients are used to compute ε for each model as a function of density, which are compared to molecular-simulation data. The form of the VEOS relating ε to density depends on the dielectric constant ε′ of the embedding medium. Three choices are examined: vacuum (ε′ = 1), self-consistent (ε′ = ε) and tin foil (ε′ = ∞). The vacuum-boundary form is found to be unreliable, losing accuracy at low density and yielding divergent results for ε at moderate densities. In contrast, the series formulated using the tin-foil boundary produces accurate and stable values of ε for almost all conditions and models examined here, even when truncated at second order (which itself is shown to be a large improvement over the first-order Clausius–Mossotti–Debye formula). [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00268976
- Volume :
- 115
- Issue :
- 8
- Database :
- Academic Search Index
- Journal :
- Molecular Physics
- Publication Type :
- Academic Journal
- Accession number :
- 122205233
- Full Text :
- https://doi.org/10.1080/00268976.2017.1301585