2018/07/20 by Mohammadhasan Dinpajooh, Dinpajooh, Mohammadhasan, Marina Guenza +1
Chemical Engineering · Engineering · Materials Science · #Block Copolymer Self-Assembly #FOS: Physical sciences #Lattice Boltzmann Simulation Studies #Rheology and Fluid Dynamics Studies #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.1807.08013
openalex publication_date 2018/07/20 · openalex created_date 2022/08/04 · openalex updated_date 2026/07/28
The integral equation coarse-graining (IECG) approach is a promising\nhigh-level coarse-graining (CG) method for polymer melts, with variable\nresolution from soft spheres to multi CG sites, which preserves the structural\nand thermodynamical consistencies with the related atomistic simulations. When\ncompared to the atomistic description, the procedure of coarse-graining results\nin smoother free energy surfaces, longer-ranged potentials, a decrease in the\nnumber of interaction sites for a given polymer, and more. Because these\nchanges have competing effects on the computational efficiency of the CG model,\ncare needs to be taken when studying the effect of coarse-graining on the\ncomputational speed-up in CG molecular dynamics simulations. For instance,\ntreatment of long-range CG interactions requires the selection of cutoff\ndistances that include the attractive part of the effective CG potential and\nforce. In particular, we show how the complex nature of the range and curvature\nof the effective CG potential, the selection of a suitable CG timestep, the\nchoice of the cutoff distance, the molecular dynamics algorithms, and the\nsmoothness of the CG free energy surface affect the efficiency of IECG\nsimulations. By direct comparison with the atomistic simulations of relatively\nshort chain polymer melts, we find that the overall computational efficiency is\nhighest for the highest level of CG (soft spheres), with an overall improvement\nof the computational efficiency being about 106-108 for various CG\nlevels/resolutions. Therefore, the IECG method can have important applications\nin molecular dynamics simulations of polymeric systems. Finally, making use of\nthe standard spatial decomposition algorithm, the parallel scalability of the\nIECG simulations for various levels of CG is presented. Optimal parallel\nscaling is observed for a reasonably large number of processors.\n