Title: Adiabatic Variations of Quantum Heat of a quantum body

Abstract: In this article it will be introduced a new theorem, can be considered a generalization of Hellmann-Feynman theorem[1]. The latter used in conjunction with the quantization of the free energy[2] of a quantum system allows to derive strightly the electronic Heat variations of a quantum electronic system, in its condensed phase of eigenstates, showing its agreement with classical thermodynamics, making then possible to desing ab inito quantum models of the electronic structure in its thermodynamical states.