Grand-Canonical Adaptive Resolution Centroid Molecular Dynamics: Implementation and Application

TL;DR

This paper introduces a new implementation of Centroid Molecular Dynamics within the Grand Canonical-like Adaptive Resolution Simulation framework, enabling efficient quantum system simulations with open boundaries and new analysis capabilities.

Contribution

The authors integrated CMD into GC-AdResS, demonstrating its effectiveness on liquid hydrogen and water, and enabling quantum-aware open boundary simulations.

Findings

Highly satisfactory reproduction of structural and dynamical properties.

Allows treatment of quantum features in open boundary systems.

Facilitates identification of essential quantum degrees of freedom.

Abstract

We have implemented the Centroid Molecular Dynamics scheme (CMD) into the Grand Canonical-like version of the Adaptive Resolution Simulation Molecular Dynamics (GC-AdResS) method. We have tested the implementation on two different systems, liquid parahydrogen at extreme thermodynamic conditions and liquid water at ambient conditions; the reproduction of structural as well as dynamical results of reference systems are highly satisfactory. The capability of performing GC-AdResS CMD simulations allows for the treatment of a system characterized by some quantum features and open boundaries. This latter characteristic not only is of computational convenience, allowing for equivalent results of much larger and computationally more expensive systems, but also suggests a tool of analysis so far not explored, that is the unambiguous identification of the essential (quantum) degrees of freedom required for a given property.