It's OK to use certain fundamental constants that come in a lot of calculators, so there's nothing we can do about that. That's OK.

当然允许使用,一些普通计算器里都有的基本常数，我们不会连这些都不让用，这是没问题的。

麻省理工公开课 - 化学原理课程节选

If you go to the Madelung calculation, it is basically this one over here.

如果你计算马德龙常数，主要基于这个。

麻省理工公开课 - 固态化学导论课程节选