Dynamic coupling of a finite element solver to large-scale atomistic simulations

• Published in: Journal of computational physics Vol. 367; pp. 279 - 294
• Main Authors: Veske, Mihkel, Kyritsakis, Andreas, Eimre, Kristjan, Zadin, Vahur, Aabloo, Alvo, Djurabekova, Flyura
• Format: Journal Article
• Language: English
• Published: Cambridge Elsevier Inc 15.08.2018; Elsevier Science Ltd
• Subjects: Atomistic simulation; Atoms & subatomic particles; Computational physics; Computer simulation; Computing time; Coupling (molecular); Differential equations; Electric field; Electric fields; Electric power distribution; Finite element analysis; Finite element method; Laplace equation; Laplace transforms; Mathematical analysis; Mesh generation; Molecular dynamics; Multiphysics; Multiscale; Scale models; Multiphysics; Finite element method; Atomistic simulation; Laplace equation; Electric field; Multiscale
• ISSN: 0021-9991; 1090-2716
• DOI: 10.1016/j.jcp.2018.04.031

We propose a method for efficiently coupling the finite element method with atomistic simulations, while using molecular dynamics or kinetic Monte Carlo techniques. Our method can dynamically build an optimized unstructured mesh that follows the geometry defined by atomistic data. On this mesh, different multiphysics problems can be solved to obtain distributions of physical quantities of interest, which can be fed back to the atomistic system. The simulation flow is optimized to maximize computational efficiency while maintaining good accuracy. This is achieved by providing the modules for a) optimization of the density of the generated mesh according to requirements of a specific geometry and b) efficient extension of the finite element domain without a need to extend the atomistic one. Our method is organized as an open-source C++ code. In the current implementation, an efficient Laplace equation solver for calculating the electric field distribution near a rough atomistic surface demonstrates the capability of the suggested approach. •A method for coupling finite element solver with atomistic simulations is proposed.•Multiscale-multiphysics problems with high computational efficiency can be solved.•The method is organized as an open-source C++ library.•An optimized unstructured mesh is dynamically built around the nanostructure.•The finite element domain can be extended and solution reused.