The influence of space group symmetry, pseudosymmetry and atomic scattering power on the path of the residual

The residual ( / is a very useful function in structure evaluation procedures. Using simple properties of the Patterson function algebraic expressions for the residual are derived. It is shown that the numerical value depends on various factors such as the presence of heavy atoms or pseudosymmetry in the structure. It appears that coincidence of interatomic vectors increases the value of the residual. The Influence of the origin peak in the Patterson function on the residual is described.