Compatible observable decompositions for coarse-grained representations of real molecular systems

Abstract

Coarse-grained (CG) observable expressions, such as pressure or potential energy, are generally different than their fine-grained (FG, e.g., atomistic) counterparts. Recently, we analyzed this so-called “representability problem” in Wagner et al. [J. Chem. Phys. 145, 044108 (2016)]. While the issue of representability was clearly and mathematically stated in that work, it was not made clear how to actually determine CG observable expressions from the underlying FG systems that can only be simulated numerically. In this work, we propose minimization targets for the CG observables of such systems. These CG observables are compatible with each other and with structural observables. Also, these CG observables are systematically improvable since they are variationally minimized. Our methods are local and data efficient because we decompose the observable contributions. Hence, our approaches are called the multiscale compatible observable decomposition (MS-CODE) and the relative entropy compatible observable decomposition (RE-CODE), which reflect two main approaches to the “bottom-up” coarse-graining of real FG systems. The parameterization of these CG observable expressions requires the introduction of new, symmetric basis sets and one-body terms. We apply MS-CODE and RE-CODE to 1-site and 2-site CG models of methanol for the case of pressure, as well as to 1-site methanol and acetonitrile models for potential energy.

Document Details

Document Type
Pub Defense Publication
Publication Date
Oct 07, 2019
Source ID
10.1063/1.5116027

Entities

People

  • Aleksander E P Durumeric
  • Gregory A. Voth
  • Jacob W Wagner
  • Thomas Dannenhoffer-Lafage

Organizations

  • Air Force Office of Scientific Research
  • National Science Foundation
  • Office of Naval Research
  • University of Chicago

Tags

Readers

  • Computational Fluid Dynamics (CFD)
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Theoretical Analysis.