J.-B. Bru and W. de Siqueira Pedra Inhomogeneous Fermi and Quantum Spin Systems on Lattices -- I (306K, pdf) ABSTRACT. We study the thermodynamic properties of a certain type of inhomogeneous Fermi and quantum spin systems on lattices. We are particularly interested in the case where the space scale of the inhomogeneities stays macroscopic, but very small as compared to the side--length of the box containing fermions or spins. The present study is however not restricted to "macroscopic inhomogeneities" and also includes the (periodic) microscopic and mesoscopic cases. We prove that -- as in the homogeneous case -- the pressure is, up to a minus sign, the conservative value of a two--person zero--sum game, named here thermodynamic game. Because of the absence of space symmetries in such inhomogeneous systems, it is not clear from the beginning what kind of object equilibrium states should be in the thermodynamic limit. Though, we give rigorous statements on correlations functions for large boxes.