Robustness of a new molecular dynamics-finite element coupling approach for soft matter systems analyzed by uncertainty quantification.

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Key parameters of a recently developed coarse-grained molecular dynamics-finite element coupling approach have been analyzed in the framework of uncertainty quantification (UQ). We have employed a polystyrene sample for the case study. The new hybrid approach contains several parameters which cannot be determined on the basis of simple physical arguments. Among others, this includes the so-called anchor points as information transmitters between the particle-based molecular dynamics (MD) domain and the surrounding finite element continuum, the force constant between polymer beads and anchor points, the number of anchor points, and the relative sizes of the MD core domain and the surrounding dissipative particle dynamics domain. Polymer properties such as density, radius of gyration, end-to-end distance, and radial distribution functions are calculated as a function of the above model parameters. The influence of these input parameters on the resulting polymer properties is studied by UQ. Our analysis shows that the hybrid method is highly robust. The variation of polymer properties of interest as a function of the input parameters is weak.