Show that for positive j and zero field (e. e., H→0 + ), the lowest energy of the lsing model with a cubic lattice is                                                 and that this lowest energy...

Show that for positive j and zero field (e. e., H→0⁺), the lowest energy of the lsing model with a cubic lattice is

and that this lowest energy corresponds to all the sp9ins aligned (either all up or all down). [Hint: The number of nearest-neighbors for any given spin is 2,4, or 6 in 1, 2, or  3 ndimensional ising model with a triangular lattice?