Theoretical Momentum Densities

This review is primarily concerned with theoretical calculations of momentum densities and Compton cross sections for molecular systems. Qualitative properties of a momentum space representation are given. A comparison between experimental and theoretical cross sections within the impulse approximation is made. Ab initio calculations for small molecules, like the nitrogen and water molecules, are studied. Various approaches to treat large molecules are studied and compared for the formamide and p-benzoquinone molecules. Some comments on calculations for solid state systems are given.