Topological analysis of electrostatic potential in SrTiO₃

The topological analysis of the electrostatic potential distribution of SrTiO₃ calculated from the experimental and theoretical electron densities was performed. It was found that the electrostatic potential and the electron density fields in SrTiO₃ had different sets of the critical points. The topological features of the electrostatic potential lead to the explicit picture of Coulomb force field, showing that the Coulomb interactions are transmitted through a crystal in the form of the 'atom-atom interactions', a network of which is a specific property of each compound.