Phase diagram of a square-well model in two dimensions

Armas-Pérez, Julio C.; Quintana-H, Jacqueline; Chapela, Gustavo A.; Velasco, Enrique; Navascués, G.

doi:10.1063/1.4863993

Cited by 14 publications

(3 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Treating their dynamics from a computational standpoint is challenging: the time evolution of these systems requires discontinuous dynamics. The conventional implementation of molecular dynamics (MD) simulations with these models is complicated by discontinuities in the potential (or more precisely, the derived forces): special procedures are needed to evolve the system in time [66][67][68][69][70][71]. This issue also affects parallelization in computer simulations because performing discontinuous dynamics requires knowing an entire configuration to account for ensuing collision dynamics.…”

Section: Introductionmentioning

confidence: 99%

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

Munguía-Valadez¹,

Chávez-Rojo²,

Sambriski³

et al. 2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 99%

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

Munguía-Valadez¹,

Chávez-Rojo²,

Sambriski³

et al. 2022

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…The HEX and BCC crystals, along with the HCP and FCC crystals and the Frank-Kasper [83,84] phase, are encountered as final stable morphologies in the crystallization of clusters formed from chains interacting with the square well attractive potential [72,78] at dilute conditions. Density-based [85,86] and geometric [72] arguments can accurately explain the dominance of non-compact crystals in specific ranges of the interaction potential in two and three dimensions.…”

Section: Methodsmentioning

confidence: 99%

Enumeration of Self-Avoiding Random Walks on Lattices as Model Chains in Polymer Crystals

Benito,

Urrutia,

Karayiannis

et al. 2023

Crystals

View full text Add to dashboard Cite

Recent simulation studies have revealed a wealth of distinct crystal polymorphs encountered in the self-organization of polymer systems driven by entropy or free energy. The present analysis, based on the concept of self-avoiding random walks (SAWs) on crystal lattices, is useful to calculate upper bounds for the entropy difference of the crystals that are formed during polymer crystallization and thus to predict the thermodynamic stability of distinct polymorphs. Here, we compare two pairs of crystals sharing the same coordination number, ncoord: hexagonal close-packed (HCP) and face centered cubic (FCC), both having ncoord = 12 and the same packing density, and the less dense simple hexagonal (HEX) and body centered cubic (BCC) lattices, with ncoord = 8. In both cases, once a critical number of steps is reached, one of the crystals shows a higher number of SAWs compatible with its geometry. We explain the observed trends in terms of the bending and torsion angles as imposed by the geometric constraints of the crystal lattice.

show abstract

“…This geometry is used in order to try to pinpoint the coexistence of the kagome lattice with uid phases, applying the spinodal decomposition procedure rst used by Chapela et al 50 for a liquid-vapor orthobaric curve of a SW in 3D, and recently applied to crystal phases of a SW in 2D. 51 This procedure consists in simulating isochores at different temperatures to obtain the density proles of the two phases in equilibrium. When dealing with a liquid-vapor orthobaric curve, it is advisable to use a density close to the critical one.…”

Section: Discrete MD Simulation Detailsmentioning

confidence: 99%

Self-assembly of kagome lattices, entangled webs and linear fibers with vibrating patchy particles in two dimensions

et al. 2014

Self Cite

View full text Add to dashboard Cite

A vibrating version of patchy particles in two dimensions is introduced to study self-assembly of kagome lattices, disordered networks of looping structures, and linear arrays. Discontinuous molecular dynamics simulations in the canonical ensemble are used to characterize the molecular architectures and thermodynamic conditions that result in each of those morphologies, as well as the time evolution of lattice formation. Several versions of the new model are tested and analysed in terms of their ability to produce kagome lattices. Due to molecular flexibility, particles with just attractive sites adopt a polarized-like configuration and assemble into linear arrays. Particles with additional repulsive sites are able to form kagome lattices, but at low temperature connect as entangled webs. Abundance of hexagonal motifs, required for the kagome lattice, is promoted even for very small repulsive sites but hindered when the attractive range is large. Differences in behavior between the new flexible model and previous ones based on rigid bodies offer opportunities to test and develop theories about the relative stability, kinetics of formation and mechanical response of the observed morphologies.

show abstract

Phase diagram of a square-well model in two dimensions

Cited by 14 publications

References 56 publications

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

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

Enumeration of Self-Avoiding Random Walks on Lattices as Model Chains in Polymer Crystals

Self-assembly of kagome lattices, entangled webs and linear fibers with vibrating patchy particles in two dimensions

Contact Info

Product

Resources

About