  Anderson model is an important model in the theory of strongly correlated
electron system. In this study, we explore the ground state of this model and
the concept of electron correlation by bipartite lattice and prove rigorously
theorems leading to the presence of spin singlet in the model. By using the
results of Ueda et al (1992) and Tian (1994), we show theoretically that the
ground state of the symmetric periodic Anderson model has a short range order
antiferromagnetism.
