Hierarchical multiscale modeling of macromolecules and their assemblies

P. Ortoleva, Abhishek Singharoy, S. Pankavich

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Soft materials (e.g., enveloped viruses, liposomes, membranes and supercooled liquids) simultaneously deform or display collective behaviors, while undergoing atomic scale vibrations and collisions. While the multiple space-time character of such systems often makes traditional molecular dynamics simulation impractical, a multiscale approach has been presented that allows for long-time simulation with atomic detail based on the co-evolution of slowly varying order parameters (OPs) with the quasi-equilibrium probability density of atomic configurations. However, this approach breaks down when the structural change is extreme, e.g., when nearest-neighbor connectivity between structural subsystems is not maintained. In the current study, a self-consistent approach is presented wherein OPs and a reference structure co-evolve slowly to yield long-time simulation for dynamical soft-matter phenomena such as structural transitions and self-assembly. The development begins with the Liouville equation for N classical atoms and an ansatz on the form of the associated N-atom probability density. Multiscale techniques are used to derive Langevin equations for the coupled OP-configurational dynamics. The net result is a set of equations for the coupled stochastic dynamics of the OPs and centers of mass of the subsystems that constitute a soft material body. The theory is based on an all-atom methodology and an interatomic force field, and therefore enables calibration-free simulations of soft matter, such as macromolecular assemblies.

Original languageEnglish (US)
Pages (from-to)4319-4335
Number of pages17
JournalSoft Matter
Volume9
Issue number16
DOIs
StatePublished - Apr 28 2013
Externally publishedYes

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ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics

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