The generalized continuous multiple step (GCMS) potential: model systems and benchmarks

Abstract

The Generalized Continuous Multiple Step (GCMS) potential is presented in this work. Due to its flexibility, repulsive and/or attractive contributions are encodable through adjustable energy and length scales. The GCMS interaction provides a continuous representation of square-well, square-shoulder potentials and their variants for implementation in computer simulations. A continuous and differentiable energy representation is required to derive forces in conventional simulation algorithms. Molecular Dynamics simulations are of particular interest when considering the dynamic properties of a system. The GCMS potential can mimic other interactions with a judicious choice of parameters due to the versatile sigmoid form. In this study, our benchmarks for the GCMS representation include triangular, Yukawa, Franzese, and Lennard-Jones potentials. Comparisons made with published data on volumetric phase diagrams, liquid structure, and diffusivity from model systems are in excellent agreement.

Structural and thermodynamic properties of fluids whose molecules interact via one-, two-, and three-step potentials

“…In the present paper we have also shown that the compressibility factor of such systems derived with the RFA, using either the virial or the compressibility routes, is also reasonably accurate. Finally, the good agreement between our results for the RDF and the simulation data (obtained with an equivalent continuous potential) [11] suggests that, at least for the structural and thermodynamic properties, replacing discrete potentials with (appropriate) continuous ones [24] does not lead to serious errors.…”

Adiabatic limit collapse and local interaction effects in non-linear active microrheology molecular simulations of two-dimensional fluids

“…46 In this work, the pHD was accomplished by using the continuous generalized continuous multiple step (GCMS) potential, which incorporates an excluded volume contribution. 47 The GCMS potential has the following formwhere q is related to the potential force and ω (positive definite) defines the spatial extent of the particle nucleus in units of σ . For hard discs, the parameter ω is arbitrary and a 0 = 0.…”

“…46 In this work, the pHD was accomplished by using the continuous generalized continuous multiple step (GCMS) potential, which incorporates an excluded volume contribution. 47 The GCMS potential has the following form…”

“…We used the GCMS potential due to its ability to provide continuous representations of discrete potentials like the square-well and square-shoulder potentials, among others. 47,48 This ability is useful for its implementation in conventional MD algorithms.…”

Special issue on soft matter research in Latin America

“…To avoid this problem there have been some works reported in the literature that provide a continuous version of some discontinuous potentials that are able to accurately describe the properties of the equivalent original discontinuous potential. With this goal in mind, the second contribution by Munguía-Valadez et al [14] presents a generalized continuous multiple step interaction potential that provides a continuous representation of the square-well, square-shoulder potentials and for some combinations of them for their implementation in simulations.…”