Coordination Polyhedra

Coordination polyhedra are drawn as convex hulls of anion neighbors around cation-like centers, following VESTA-style conventions: vertices must be non-metal neighbors more electronegative than the center, lying within 30% of the shortest such bond (so noisy over-long bonds don't inflate e.g. PO₄ tetrahedra). To keep the structural framework readable, spectator A-site cations (alkali metals, Ca/Sr/Ba), very high-coordination hulls (CN > 8), and weakly-bound lone-pair cations (e.g. Bi³⁺) are skipped whenever framework polyhedra exist — toggle any element back on via the Centers checkboxes in the controls pane. Vertices come from the same bond graph as the rendered bonds, so polyhedra respect the bonding strategy, bond edits, and hidden elements, and boundary-truncated copies in supercells are skipped automatically.

Molecules

Polyhedra default to crystals only (show_polyhedra: 'crystals') but also work for molecules when set to 'always' or 'molecules', like this SF₆ octahedron. Methane shows none: carbon is more electronegative than hydrogen, so CH₄ is not treated as a coordination environment.