Quantal Density Functional Theory [Paperback]

Density functional theory is an important and widely used tool in many-body physics that has found applications in atomic, molecular, solid-state and nuclear physics. It is used principally to determine the electronic structure of these complex systems. Sahni has developed a new approach, termed quantal density functional theory, which simplifies the process of solving the computational problem and at the same time, gives insight into the underlying quantum mechanics. Further, the book describes Schr?dinger theory from the new perspective of fields and quantal sources. It also explains the physics underlying the functionals and functional derivatives of traditional DFT

Quantal density functional theory (Q-DFT) is a new local effective potential energy theory of the electronic structure of matter. It is a description in terms of classical fields that pervade all space, and their quantal sources. The fields, which are explicitly defined, are separately representative of the many-body electron correlations present in such a description, namely, those due to the Pauli exclusion principle, Coulomb repulsion, correlation-kinetic, and correlation-current-density effects. The book further describes Schr?dinger theory from the new perspective of fields and quantal sources. It also explains the physics underlying the functionals and functional derivatives of traditional DFT.1. Introduction.- 2. Schr?dinger Theory from the Perspective of Classical Fields Derived from Quantal Sources.- 3. Quantal Density Functional Theory.- 4. The Hohenberg-Kohn Theorems and Kohn-Sham Density Functional Theory.- 5. Physical Interpretation of Kohn-Sham Density Functional Theory.- 6. Quantal Density Functional Theory of the Density Amplitude.- 7. Quantal Density Functional Theory of the Discontinuity in the Electron-Interaction Potential Energy.- 8. Further Insights Derived Via Quantal Density Functional Theory.- 9. Epilogue.- Appendices.- A. Proof of the Pure State Differentilã'