Crystal

What about two-dimensional crystals? --MassimoNespolo 13:59, 3 April 2009 (BST)

First, the article points to a 2D crystal and not a crystal. Second, the name was coined by the authors of the article and they are the sole responsible for their definition. Apparently this 2D crystal can only be dealt with on a Si substrate and can only observed with with HREM or AFM. We are dealing here with a very special case of some atomic arrangements which can be formed in HREM. Should any mono or di-atomic surface which can be observed in EM be called 2D crystal?

I would be reluctant to modify the definition of crystals just to include atomic layers