I just had my second solid state physics lecture and we were talking about bravais lattices. As far as I understand a Bravais lattice is an infinite network of points that looks the same from each point in the network. For example:
would be a Bravais lattice. On the other hand, this:
is not a bravais lattice because the network looks different for different points in the network. However, in lecture it was briefly mentioned that we could make this into a Bravais lattice by choosing a suitable basis:
The problem is, I don't really see how that changes anything. The positions of the atoms/points didn't change relative to each other.
1) Do I have to imagine the two atoms "combined" into one? If I do that, where is the new "2-in-1" atom located?
2) How can I construct a primitive vector that will go to this point?
3) Is there an infinite amount of points/atoms I can combine? Are there an infinite amount of basis I can choose?
4) Would the Wigner-Seitz cell have to be over two points if I choose a two atom basis?