Chemical Bond Formation and Rupture Processes: An Application of DFT–Chemical Pressure Approach

Very recently, we have analyzed the nature of chemical interactions in a wide variety of molecules and materials using the chemical pressure (CP) approach. We have shown how this newly developed formalism can be used to identify and visualize different types of chemical bonds based on the attractive and repulsive forces between the constitutive atoms of molecules and materials. In this article, we illustrate the capability of the CP approach to clearly track the bond formation and rupture processes in crystalline solids. Using the indium phosphide crystal as a model system, the evolution of its chemical bonding network is investigated in two different phenomena: (i) along a pressure-induced phase transition mechanism and (ii) after electron beam irradiation of the unit cell. The CP maps show distinctive features related to the local atomic interactions in the crystal structure, providing insights into the chemical nature of any distorted/defective structure throughout these transformation processes. This is accomplished by searching for the appearance/disappearance of absolute minima of negative CP along bonding interatomic paths and of zero CP contour lines surrounding the metallic atoms.