style identification - What is this atom affect called?

I've seen lots of websites with these types of effects/design in the background. What is it called?

Source: https://www.simpla.io/

Answer

I believe called a Network Graph diagram, and it's associated with a the mathematical graph theory

https://en.wikipedia.org/wiki/Graph_theory

That said, I'm not sure if there might be perhaps a more Graphic Design naming for it.

Edit: Here's an example of a javascript library to create one:

http://christophergandrud.github.io/d3Network/

It also seems to use the term Network Graph, so that's your best bet.