> Hi all, > > I've got a (silly, I'd say) question regarding the subroutine reclat. I > wanted to see the cartesian components of the reciprocal lattice vectors. > when I take a supercell of graphene with > lattice vectors along x and y, I get: > > reclat: Unit cell vectors (Bohr): > a1: 64.2734938385 0.0000000000 0.0000000000 > a2: 0.0000000000 9.2770797408 0.0000000000 > a3: 0.0000000000 0.0000000000 32.4697790909 > reclat: Reciprocal lattice vectors, not scaled by 2*pi: > b1: 0.0977570213 0.0000000000 0.0000000000 > b2: 0.0000000000 0.6772805110 0.0000000000 > b3: 0.0000000000 0.0000000000 0.1935087174 > > Now, the direct lattice vectors are correct, but I would expect that > $b_{1x}=2*pi*a_{2y}$; instead $b_{1x}=2*pi*a_{2x}$, and something > analogous happens for $b_{2y}$. Am I missing something, or is the > condition > > $\vec b_{i} \dot \vec a_{j}$ > > not obeyed by the subroutine reclat?
Dear Marcos - Yes it is: each reciprocal vector is orthogonal to TWO OTHER ones in the direct lattice. That means for orthorhombic lattices: each reciprocal one is aligned with its corresponding direct one, and has its recioprocal length. Exactly as you have it... Best regards Andrei Postnikov