I want to calculate magnitude of k point(in Brillouin zone) of graphene which has hexagonal unit cell. The lattice parameters of graphene are given below:
If I consider the folloing k point
cart. coord. in units 2pi/alat
k( 44) = ( 0.3000000 0.5773503 0.0000000), wk = 0.0300000
How can I calculate the magnitude of the |k| in the hexagonal reciprocal unit cell? considering that I know the value of (kx, ky, 0). The lattice is a parallelogram so that |k| does NOT simply equal to sqrt(kx^2+ky^2), right?