If we have, coming along this z axis, another carbon atom, we can actually form one bond between the two carbon atoms there.

如果我们在z方向，有另外一个碳原子，我们可以在,两个碳原子之间形成一个键。

麻省理工公开课 - 化学原理课程节选

Essentially what we're seeing is overlapping in this z axis here.

本质上我们看到的是在z轴这里的交叠。

麻省理工公开课 - 化学原理课程节选

And the convention is that when two atoms bond, they bond along the z-axis.

我们的惯例是，两个轨道成键，键轴为Z轴。

麻省理工公开课 - 固态化学导论课程节选

Specifically, it's always the z that forms the sigma orbital, and the reason is at least at a minimum for this class we always define the internuclear axis as the z axis, so this is always the z axis, so it's always going to be the 2 p z's that are coming together head-on.

特别的，z总是形成sigma轨道，这是因为至少在这个课里面,我们总是定义核间轴为z轴，所以这总是z轴，所以2pz轨道总是,朝一个方向出现。

麻省理工公开课 - 化学原理课程节选

So, if we think about this z bonding axis between the two carbon atoms, we can picture overlap of those s p hybrid orbitals, and then we can also picture bonding to hydrogen.

如果我们考虑,两个碳原子之间的z成键轴，我们可以画出sp杂化轨道的交叠，我们也可以画出和氢原子的成键。

麻省理工公开课 - 化学原理课程节选

So what we can say is look at each of these separately, so if we start with looking at the 2 p z orbital, the highest probability of finding an electron in the 2 p z orbital, is going to be along this z-axis.

我们可以来分别看看这些图，首先来看看2pz轨道，在2pz轨道里,找到电子的最大概率，是沿着ｚ轴。

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

And remember for this class, we always define z as the internuclear or the bond axis.

记住在我们的课堂上，我们总是把z方向定义为核间轴的方向。

麻省理工公开课 - 化学原理课程节选

We have two of them on the z-axis like this.

他们俩的z轴都这样。

麻省理工公开课 - 固态化学导论课程节选

These are both z-axis.

他们俩都是z轴。

麻省理工公开课 - 固态化学导论课程节选