The cranking term breaks the time reversal symmetry, and the projection of the single particle angular momentum on the intrinsic symmetric axis is no longer a good quantum number.

推转项的引入破坏了时间反演对称性，单粒子角动量在内禀对称轴上的投影量子数已不再是好量子数。

youdao

The other main difference that we're really going to get to today is that in multi-electron atoms, orbital energies depend not just on the shell, which is what we saw before, not just on the value of n, but also on the angular momentum quantum l number. So they also depend on the sub-shell or l.

我们今天要讨论的,另一个很重要的区别就是,在多电子原子中，轨道能力不仅仅依赖于，我们以前看到的外层，不仅仅依赖于n的值，而是与角动量量子数也有关系,所以它们也依赖于亚外层或者。

麻省理工公开课 - 化学原理课程节选