PATTERNS OF BONDLENGTH VARIATION FOR ATOMS BONDED TO OXYGEN

A complete survey of bond lengths from the Inorganic Crystal Structure Database (ICSD) is presented for all atoms of the Periodic Table of Elements, bonded to oxygen and in different oxidation states and coordination numbers. Rigorous filtering of 135,000 crystal structures resulted in the collection of 136 different ions in 473 configurations (coordination numbers) and 33,546 cation coordination polyhedra, for a total of 189,430 bond distances. The bondlength data, shown as histograms for every configuration, yields an immense amount of information. Of particular interest here is the visual aspect of the histograms. Comparing these plots under different criteria (e.g. configuration, family, period) shows trends across the periodic table of elements that are less obvious in individual case studies. Subtleties in bondlength distributions for specific ions become more evident, and allow us to examine the underlying principles giving rise to these distributions. While known electronic effects such as the “Jahn-Teller” effect are observed where theory predicts, the bond-length distributions of some other ions deviate from a normal distribution to various degrees, from shoulders on the distribution of “spherical” atoms, to multimodal distributions in elements of later periods.