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Quantum topological atoms in the protein crambin provide atomic multipole moments to realize more accurate electrostatics, as shown by Yongna Yuan, Matthew Mills, and Paul Popelier on page 343. These atoms do not overlap; they have finite volumes and shapes that are primarily determined by the local environment. The cover, designed by Tim Hughes, shows critical points of the type (3,−1) (small purple spheres), marking special atom–atom interactions with their associated atomic interaction lines (solid and dashed).