Ah, but density is mass over volume.

但密度是质量除以体积

耶鲁公开课 - 基础物理课程节选

So, that's probability density, but in terms of thinking about it in terms of actual solutions to the wave function, let's take a little bit of a step back here.

这就是概率密度，但作为,把它当成是，波函数的解，让我们先倒回来一点。

麻省理工公开课 - 化学原理课程节选

So pi bonds have electron density both above and below the bond axis, but they actually have a nodal plane at this z, this bond axis here.

键在键轴之上,和之下都有电子密度，但它们在z方向有节面，这是键轴的地方。

麻省理工公开课 - 化学原理课程节选