Zu was best known for his calculation of pi (π).

祖以计算 pi（Π）而闻名。

youdao

So let's have a clicker question here on how many total pi bonds do you expect to see in benzene?

让我们来做个课堂习题,你们觉得苯环里有一共多少个π键？

麻省理工公开课 - 化学原理课程节选

There's absolutely no reason I couldn't have switched it around and said that instead the pi orbitals form between these atoms instead of those first atoms I showed.

我完全没有理由,不能把它转过来,现在π键在这些原子间,而不是我开始展示的那些原子间。

麻省理工公开课 - 化学原理课程节选

And so both of these lobes together constitute a pi bond.

上下两片叶一起组成了一根π键。

麻省理工公开课 - 固态化学导论课程节选