Hello! I am a student and have just started studying about graphene. However I am having quite a lot of problems understanding the crystal structure, specifically, I am unable to place certain terms. These being : 1. Basis vectors.(I do understand what a basis vector is but am having difficulties in realizing them in the hexagonal structure.) 2. Reciprocal lattice, brillouin zone. I would be very thankful should someone help me out or suggest references.