... critical spheres which correspond to the twop ossible structures with rank 1: (1, −1) and (1, +1).Studying the derived functions from the first order density brings forthimportant data. For example, ... than that obtained using HF.[13]2.6. BLOCH THEOREM 972.6 Bloch theorem [138, 212, 232]The study of condensed matter is a subject field of physics focusing on themicroscopic and macroscopic ... properties of thecondensed phase. A branch of the condensed matter physics, the largest one, isthe study of solid-state matter: atoms packed tightly under strong interactionforces responsible of...