NQCDynamics.jl: A Julia Package for Nonadiabatic Quantum Classical\n Molecular Dynamics in the Condensed Phase

Abstract

Accurate and efficient methods to simulate nonadiabatic and quantum nuclear\neffects in high-dimensional and dissipative systems are crucial for the\nprediction of chemical dynamics in condensed phase. To facilitate effective\ndevelopment, code sharing and uptake of newly developed dynamics methods, it is\nimportant that software implementations can be easily accessed and built upon.\nUsing the Julia programming language, we have developed the NQCDynamics.jl\npackage which provides a framework for established and emerging methods for\nperforming semiclassical and mixed quantum-classical dynamics in condensed\nphase. The code provides several interfaces to existing atomistic simulation\nframeworks, electronic structure codes, and machine learning representations.\nIn addition to the existing methods, the package provides infrastructure for\ndeveloping and deploying new dynamics methods which we hope will benefit\nreproducibility and code sharing in the field of condensed phase quantum\ndynamics. Herein, we present our code design choices and the specific Julia\nprogramming features from which they benefit. We further demonstrate the\ncapabilities of the package on two examples of chemical dynamics in condensed\nphase: the population dynamics of the spin-boson model as described by a wide\nvariety of semi-classical and mixed quantum-classical nonadiabatic methods and\nthe reactive scattering of H2 on Ag(111) using the Molecular Dynamics with\nElectronic Friction method. Together, they exemplify the broad scope of the\npackage to study effective model Hamiltonians and realistic atomistic systems.\n