Introduction

Bridging the gas and condensed phases for metal-atom encapsulating silicon- and germanium-cage superatoms: electrical properties of assembled superatoms

“…Certain NCs with adequate size and elemental composition make their electronic structure similar to that of atoms in the periodic table. 6,34,35 Like atoms form an electronic shell composed of atomic orbitals of s, p, d, f,… SAs have resembled orbitals called superatomic orbitals that are delocalized to overall SA denoted as S, P, D, F,… with capital letters representing the angular momentum of the superatomic orbitals. The concept of SAs can explain various features of SAs in terms of the electronic shell model.…”

Principles of isomer stability in small clusters

“…This suggests that it is possible to regard particular clusters as superatoms. 11,13,16,36–38 The concept of magic clusters paves the way to superatoms physics. Following the findings on the halogen character of the Al 13 cluster, various research groups, such as the experimental group of Castleman and Khanna's theory group 12,13,39 explored the concept of superatoms.…”

Phase Stability, Strong Four-Phonon Scattering, and Low Lattice Thermal Conductivity in Superatom-Based Superionic Conductor Na3OBH4

“…Superatom refers to a stable atomic cluster composed of multiple atoms with the electronic structure and chemical properties similar to that of a single atom in the periodic table . By combining atomic precision, synthetic flexibility, and tunable properties, superatoms emerge as versatile building blocks for superatom-based materials that exhibit properties very different from those based on individual atoms .…”

“…It is well known that superatom-based materials have two characteristic length scales: the interatomic distance inside the superatom and the inter-superatom distance, thus forming rich bonding hierarchies. , The concept of “rattler” atoms (loosely bound guest atoms in an oversized atomic cage) in “rattler-type” materials classes, such as clathrates , and skutterudites, , would extend to superatomic rattlers in superatom-based frameworks. Furthermore, the coupling of intra-superatom and inter-superatom vibrations would significantly affect the lattice stability, phonon–phonon interaction pattern, and scattering intensity. − According to Slack rules, strong anharmonicity, complex crystal structure, and weak bonding strength would greatly suppress the lattice thermal conductivity of atom- and, especially, superatom-based electrolytes. , However, no work has been reported so far to study the lattice dynamics and thermal conduction of the experimentally synthesized Na 3 OBH 4 , which motivates us to carry out this study.…”