Adaptive molecular resolution via a continuous change of the phase space dimensionality

TL;DR

This paper introduces a theoretical framework for adaptively changing the resolution of molecular simulations, allowing for more efficient and flexible modeling of complex systems by smoothly varying phase space dimensionality.

Contribution

It presents a novel formalism for coupling different resolution regimes in molecular simulations through a continuous change in phase space dimensionality.

Findings

Develops a geometry-induced phase transition analogy.

Derives a fractional degrees of freedom equipartition theorem.

Provides a formal basis for multiscale simulation methods.

Abstract

For the study of complex synthetic and biological molecular systems by computer simulations one is still restricted to simple model systems or to by far too small time scales. To overcome this problem multiscale techniques are being developed for many applications. However in almost all cases, the regions of different resolution are fixed and not in a true equilibrium with each other. We here give the theoretical framework for an efficient and flexible coupling of the different regimes. The approach leads to an analog of a geometry induced phase transition and a counterpart of the equipartition theorem for fractional degrees of freedom. This provides a rather general formal basis for advanced computer simulation methods applying different levels of resolution.