So every atom. Or even if it's a molecular crystal, every molecule, they're all in the ground state.
那么每个原子，或者说对于分子晶体，每个分子，他们都处于基态。
2
There is a stable ground state of the atom.
原子有一个稳定的基态。
3
So, if we're talking about five different orbitals and we're talking about a ground state atom, we know that we just need to start at the bottom and work our way out up.