Non-recursive Chadi-Cohen integration over the Brillouin zone of cubic crystals

We give closed-form non-recursive formulae for the Chadi-Cohen sets of special points associated with the bce and fee symmetries. The expressions are valid for arbitrary order n, which enters them as a parameter. This ameliorates the situation of the Chadi-Cohen method of integration over Brillouin zones, whose application to high-precision calculations has been severely limited by the difficulty of generating sets of special points of order higher than n = 2.