Ab-Initio Molecular Dynamics Acceleration Scheme with an Adaptive Machine Learning Framework

Abstract: Quantum mechanics based ab-initio molecular dynamics (MD) simulation schemes offer an accurate and direct means to monitor the time-evolution of materials. Nevertheless, the expensive and repetitive energy and force computations required in such simulations lead to significant bottlenecks. Here, we lay the foundations for such an accelerated ab-initio MD approach integrated with a machine learning framework. The proposed algorithm learns from previously visited configurations in a continuous and adaptive manner on-the-fly, and predicts (with chemical accuracy) the energies and atomic forces of a new configuration at a minuscule fraction of the time taken by conventional ab-initio methods. Key elements of this new accelerated ab-initio MD paradigm include representations of atomic configurations by numerical fingerprints, the learning algorithm, a decision engine that guides the choice of the prediction scheme, and requisite amount of ab-initio data. The performance of each aspect of the proposed scheme is critically evaluated for Al in several different chemical environments. This work can readily be extended to address non-elemental compounds, and has enormous implications beyond ab-initio MD acceleration. It can also lead to accelerated structure and property prediction schemes, and accurate force-fields.