Splitting of Degenerate Superatomic Molecular Orbitals Determined by Point Group Symmetry

Abstract

We first confirm an idea obtained from first-principles calculations, which is in line with symmetry theory: Although superatomic molecular orbitals (SAMOs) can be classified according to their angular momentum similar to atomic orbitals, SAMOs with the same angular momentum split due to the point group symmetry of superatoms. Based on this idea, we develop a method to quantitatively modulate the splitting spacing of molecular orbitals in a superatom by changing its structural symmetry or by altering geometric parameters with the same symmetry through expansion and compression processes. Moreover, the modulation of the position crossover is achieved between the lowest unoccupied molecular orbital and the highest occupied molecular orbital originating from the splitting of different angular momenta, leading to an effective reduction in system energy. This phenomenon is in line with the implication of the Jahn–Teller effect. This work provides insights into understanding and regulating the electronic structures of superatoms.