Isomerization Energy Decomposition Analysis for Highly Ionic Systems: Case Study of Starlike E5Li7+ Clusters

The most stable forms of E₅Li₇⁺ (E=Ge, Sn, and Pb) have been explored by means of a stochastic search of their potential‐energy surfaces by using the gradient embedded genetic algorithm (GEGA). The preferred isomer of the Ge₅Li₇⁺ ion is a slightly distorted analogue of the D_5h three‐dimensional seven‐pointed starlike structure adopted by the lighter C₅Li₇⁺ and Si₅Li₇⁺ clusters. In contrast, the preferred structures for Sn₅Li₇⁺ and Pb₅Li₇⁺ are quite different. By starting from the starlike arrangement, corresponding lowest‐energy structures are generated by migration of one of the E atoms out of the plane with the a corresponding rearrangement of the Li atoms. To understand these structural preferences, we propose a new energy decomposition analysis based on isomerizations (isomerization energy decomposition analysis (IEDA)), which enable us to extract energetic information from isomerization between structures, mainly from highly charged fragments.