超原子是一个表现出元素的原子性质的原子团簇。钠原子从蒸汽冷却时自然凝结成团簇时优先含有原子个数为（2，8，20，40，58等）的幻数。前两个可以被看作是需要分别填充的第一和第二壳的电子数目。超原子中的自由电子占据整个的原子团外层，而不是分散在单个的原子上。价电子光谱性质及团簇作为整体所具有的化学价态要与相应的原子相似。根据超原子特殊的物理化学特性及潜在的应用价值，有人提出了三维元素周期表的概念。比如TiO、ZrO和WC分别是金属Ni、Pd和Pt的“超级原子”。

A superatom is any cluster of atoms that seem to exhibit some of the properties of elemental atoms.

Sodium atoms, when cooled from vapor, naturally condense into clusters, preferentially containing a magic number of atoms (2, 8, 20, 40, 58, etc.). The first two of these can be recognized as the numbers of electrons needed to fill the first and second shells, respectively. The superatom suggestion is that free electrons in the cluster occupy a new set of orbitals that are defined by the entire group of atoms, i.e. cluster, rather than each individual atom separately (non-spherical or doped clusters show deviations in the number of electrons that form a closed shell as the potential is defined by the shape of the positive nuclei.) Superatoms tend to behave chemically in a way that will allow them to have a closed shell of electrons, in this new counting scheme. Therefore, a superatom with one more electron than a full shell should give up that electron very easily, similar to an alkali metal, and a cluster with one electron short of full shell should have a large electron affinity, such as a halogen.