Relooking into the Dynamics of B13+ Rotor Through Core–Peripheral Electron Density Separation and a Novel Approach of Reduced Electron Density Analysis of AdNDP Orbitals

In this study, the core and periphery of the B₁₃⁺ cluster have been unveiled by employing a novel approach—Reduced Electron Density Analysis of adaptive natural density partitioning (AdNDP) Orbitals—to explore its rotor action. The central core of the cluster, acting as a “control unit”, governs the transformation between the ground state (GS) and transition state (TS). Core–peripheral electron density separation alongside AdNDP analysis has revealed how electron density shifts within the core dictate the cluster's structural transitions. For the first time, the reduced electron density of AdNDP orbitals provides a clearer visualization of the core's subtle rotational movements, offering an unprecedented look at the mechanism behind the GS-TS interconversion. The iso-surface plots highlight the influence of three core atoms, particularly one in the GS and two atoms in the TS, which serve as “master atoms” guiding the transformation. This work introduces a new methodology for investigating nanoscale transformations, laying the groundwork for future research in controlling nanomotors and designing advanced materials.