Bottom-up coarse-graining scheme for the preservation of relevant slow degrees of freedom in soft materials.*

Coarse graining approaches aim to recover relevant physical phenomena of molecular systems with computer simulations at lower resolutions than an atomistic representation. Ideally, the lower resolution still accounts for the degrees of freedom necessary to recover the correct physical behavior of the high resolution reference system, but with reduced computational cost. We make the argument that in soft matter contexts correct physical behavior corresponds to reproducing the long-time dynamics of a system.Thus, the retained degrees of freedom should correctly capture the rare-event transitions relevant for the long-time dynamics. Here, we propose a bottom-up coarse-graining scheme that correctly preserves the relevant slow degrees of freedom, and we test this idea for systems of increasing complexity. We show that in contrast to existing coarse-graining schemes, such as those from information theory or structure-based approaches, only the novel scheme is able to recapitulate the slow timescales of the system of interest.