Figure 13.

Frequency for which bond-topological effects (BTE), multiple-bond formation (π), the strong (JTEs) and weak (JTEw) Jahn–Teller effects, the pseudo Jahn–Teller effect (PJTE) and crystal-structure effects (CSE) are the main (dark grey) and minor (light grey) causes of bond-length variation underlying the ion configurations of Table 4 ▸. These data are necessarily biased toward anomalous bond-length distributions, whereas the BTE is ubiquitous across all ion configurations. Mean Δ_topol and Δ_cryst values (right-hand axis) are calculated using those polyhedra for which the given effect is the main cause of bond-length variation. The numbers atop each bar represent the sample size.