Issue 19, 2020

Adiabatic motion and statistical mechanics via mass-zero constrained dynamics

Abstract

In recent work [Coretti et al., J. Chem. Phys., 2018, 149, 191102], a new algorithm to solve numerically the dynamics of the shell model for polarization was presented. The approach, broadly applicable to systems involving adiabatically separated dynamical variables, employs constrained molecular dynamics to strictly enforce the condition that the force on the fast degrees of freedom, modeled as having zero mass, is null at each time step. The algorithm is symplectic and fully time reversible, and results in stable and efficient propagation. In this paper we complete the discussion of the mechanics of mass-zero constrained dynamics by showing how to adapt it to problems where the fast degrees of freedom must satisfy additional conditions. This extension includes, in particular, the important case of first principles molecular dynamics. We then consider the statistical mechanics of the mass-zero constrained dynamical system demonstrating that the marginal probability sampled by the dynamics in the physical phase space recovers the form of the Born–Oppenheimer probability density. The effectiveness of the approach and the favorable scaling of the algorithm with system size are illustrated in test calculations of solid Na via orbital-free density functional dynamics.

Graphical abstract: Adiabatic motion and statistical mechanics via mass-zero constrained dynamics

Article information

Article type
Paper
Submitted
15 جمادى الأولى 1441
Accepted
11 رجب 1441
First published
11 رجب 1441

Phys. Chem. Chem. Phys., 2020,22, 10775-10785

Adiabatic motion and statistical mechanics via mass-zero constrained dynamics

S. Bonella, A. Coretti, R. Vuilleumier and G. Ciccotti, Phys. Chem. Chem. Phys., 2020, 22, 10775 DOI: 10.1039/D0CP00163E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements