Optimal meshes for integrals in real- and reciprocal-space unit cells

We present a detailed method to construct uniform meshes for fast Fourier transforms in electronic-structure calculations. We show that a drastic reduction in the mesh size can be frequently achieved by using an unconventional set of primitive lattice vectors. The same method can be applied also to obtain optimum sets of special points for Brillouin-zone integrals, generalizing previous schemes.