A Novel Pathway from DFT to CI

Noble gases are of great importance in the development of new theoretical tools before studying more complex and interesting systems, such as molecules and clusters, because their properties are well established experimentally. Noble gas atoms are also small enough so when testing a new theory, basis set dependencies can be ruled out. Here we describe a method for approaching configuration interaction accuracy by analyzing past results obtained by density functional theory. We present core level excitations for Neon and other systems.