Local Refinements in Classical Molecular Dynamics Simulations

2nd International Conference on Mathematical Modeling in Physical Sciences 2013

物理学;数学

Fackeldey, Konstantin^1 ; Weber, Marcus^1

Zuse Institute Berlin (ZIB), Takustr. 7, 14196 Berlin, Germany^1

关键词: Classical molecular dynamics;    Classical trajectories;    Computational feasibility;    Dynamical simulation;    Empirical force fields;    Molecular simulations;    Moving least squares method;    Partition of unity;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/490/1/012016/pdf
DOI  :  10.1088/1742-6596/490/1/012016

来源: IOP

【 摘 要 】

Quantum mechanics provide a detailed description of the physical and chemical behavior of molecules. However, with increasing size of the system the complexity rises exponentially, which is prohibitive for efficient dynamical simulation. In contrast, classical molecular dynamics procure a coarser description by using less degrees of freedom. Thus, it seems natural to seek for an adequate trade-off between accurateness and computational feasibility in the simulation of molecules. Here, we propose a novel method, which combines classical molecular simulations with quantum mechanics for molecular systems. For this we decompose the state space of the respective molecule into subsets, by employing a meshfree partition of unity. We show, that this partition allows us to localize an empirical force field and to run locally constrained classical trajectories. Within each subset, we compute the energy on the quantum level for a fixed number of spatial states (ab initio points). With these energy values from the ab initio points we have a local scattered data problem, which can be solved by the moving least squares method.