Discontinuous Molecular Dynamics for Semi-Flexible and Rigid Bodies

TL;DR

This paper introduces a comprehensive framework for event-driven molecular dynamics simulations of semi-flexible and rigid bodies, offering two approaches based on Lagrangian mechanics and explicit rigid body equations.

Contribution

It presents two novel methods for simulating semi-flexible and rigid bodies, including algorithms for event detection and handling missed interactions.

Findings

Two approaches for simulating semi-flexible and rigid bodies.

Efficient algorithms for event time prediction.

Discussion on handling missed interaction events.

Abstract

A general framework for performing event-driven simulations of systems with semi-flexible or rigid bodies interacting under impulsive torques and forces is outlined. Two different approaches are presented. In the first, the dynamics and interaction rules are derived from Lagrangian mechanics in the presence of constraints. This approach is most suitable when the body is composed of relatively few point masses or is semi-flexible. In the second method, the equations of rigid bodies are used to derive explicit analytical expressions for the free evolution of arbitrary rigid molecules and to construct a simple scheme for computing interaction rules. Efficient algorithms for the search for the times of interaction events are designed in this context, and the handling of missed interaction events is discussed.