How to change atoms symbol in a structure?

How to change atoms symbol in a structure?

Zahra (guest) 09 Aug 2013 23:31

Hi;
I am going to create a structure with 5 layers of Cu and two layers of Co. But instead of creating these structures seperately, I want to make a 7 layer structure of Cu and then change its symbol for 2 top layers to Co. I am new to python and ASE and I don't know how should I do it?
Would you please let me know if you have any idea?

Thanks;
Zahra