Computational approaches of relativistic models in quantum chemistry

Abstract

Publisher Summary This chapter focuses on computational approaches of relativistic models in quantum chemistry. The chapter illustrates that the use of ab initio relativistic calculations are mandatory to obtain an accurate description of heavy atoms and ions. It is important whether one is considering highly charged ions, inner shells of neutral or quasi neutral atoms or outer shells of very heavy atoms. The chapter illustrates that from a physics point of view, the natural formalism to treat such a system is Quantum Electrodynamics (QED), the prototype of field theories. In addition, the only known method to do an accurate calculation is to attempt to treat to all orders the electron-electron interaction, and reserve QED for radiative corrections (interaction of the electron with its own radiation field, creation of virtual electron-positron pairs).