A set of eight valence electrons in an atom or ion , forming a stable configuration 八重态在一个原子或离子中，形成稳定组态的一组八个化合价电子
2.
The minima of this multidimensional landscape ? the bottoms of depressions where a ball could come to rest ? correspond to the stable configurations of spacetime ( including branes and fluxes ) , which are called stable vacua 由于这个多维地景的极小值（球可以停驻的凹陷底部） ，对应著时空的稳定组态（包括膜与通量） ，所以称为稳定真空。
