Electronic Structures and Excited State Dynamics of Superatoms

As multi-atomic complex systems belonging to molecules, superatoms possess unique molecular orbitals that can be classified according to the symmetry of the electronic orbital angular momentum, similar to atoms. They are expected to show similarstructural characteristics to atoms, and present profound and complex physical connotations in their interactions. Superatatoms are considered to be artificial motifs with both atomic and molecular characteristics, and research on them offers important prospects to simulate and even replace atoms so as to realize the function of the artificial motifs. Building new structures and even devices from superatoms offers a promising way to overcome the structural and functional limitations of atoms as motifs and develop high performance and even revolutionary applications of superatoms. In order to move towards the goal of advanced applications of superatoms, it is very urgent to reveal the underlying physics of superatoms at the atomic level in order to facilitate their applications. Building on the research in conventional atomic and molecular physics and using the related methodologies, this project will systematically study the electronic structures and excited state dynamics of several representative superatoms, focusing on their following characteristics: electron-vibration coupling, charge-energy transfer processes, electron transition between energy levels, and electron tunneling processes. Specifically, combining state-of-the-art first-principles calculations and dynamics simulations, wewill investigate excited state dynamics and electron tunneling, possibly extending our investigation to complex systems involving environmental confinements. We will select several representative superatomic structures for study, including the widely reportedC60, Au20 and carbon-based structures encapsulating coinage metals, as well as some of the boron and boron nitride cage structures we have recently identified, as the basic research systems. We expect to uncover the following of superatoms with focuses ontheir distinctions with those of atoms: the relationship between the electronic structures and excited state properties, the rules of electronic transition, oscillator strength, the features of electron delocalization, the characteristics of vibrational relaxation, internalconversion and intersystem crossing, electronic excitation induced isomerizations, the geometry and lifetime of excitons, the charge and energy transfer processes, the effects of environmental confinement on excited states, the chemical reaction processes relatedto excited states, and even the electron tunneling processes. The completion of the project will promote the development of superatomic physics and lay the foundation for future development in the relevant fields.