What's the difference between 之间 and 中间? 之间 means between (no more than 2), so these are acceptable:


我和他之间
我们之间 (between us two)


Not acceptable:


学生们之间


中间 means among (more than 2), so this is acceptable:


学生们之间


And this isn't:


我和他之间


I'm trying to understand the difference between 之间 and 中间，is the above right? Moreover are 中间 and 中 the same（我们中（间））？
I think there's a couple more important distinctions. 

中间 is used for when talking about the physical location being in the center/between.

ie. You would say:


  箱子的中间有个人。


之间 is used when abstract things are in the center/between. This applies to things like numbers.

ie. You would say:


  我们之间没有爱。


Here's a specific example of how the two words have a different meaning.

我们中间有障碍。 : There are (physical) obstacles between us.

我们之间有障碍。 : There are (mental) obstacles between us.