General reverse mapping of phase-separating polymers — Bridge from DPD to atomistic MD for star-polymer assemblies

Polymer self-assembly is inherently multiscale: coarse-grained (CG) simulations capture mesoscale organization, whereas all-atom (AA) molecular dynamics resolves local interactions. We present ANY-RM, a fast and straightforward reverse-mapping method that reconstructs AA star-polymer structures from a dissipative particle dynamics configuration by converting bead coordinates into a concentration-distribution field and placing atoms to satisfy local composition constraints. The AA models retain CG phase separation while restoring atomistic detail. Static structure agrees across scales. Our method enables the investigation of both large-scale organization and detailed molecular interactions, offering a comprehensive understanding of polymer self-assembly across multiple scales.