Cartoon of the coarse-graining process proposed by Bianca Mladek and co-workers for modeling metal nanoparticles coated with DNA strands. The original particle (top) is a gold crystalline core made of many atoms (shown in enlargement). The core is functionalized with DNA single strands, whose last group of bases (green) can bind with complementary strands attached to a distinct nanoparticle. In the first step of the coarse-graining process (middle), the core is condensed into a single particle and the DNA sequence is treated as a charged polymer, in which each site represents a group of bases (red if not binding, green if binding). In the next coarse-graining step (bottom), the nonbinding part of all polymers is condensed into a single soft sphere (pink), while each binding sequence is condensed into a separate soft particle (green).