# Development of a Correction Term for the Kinetic Energy Density Functional

Thesis

Density functional theory (DFT) is a useful theoretical and computational tool for electronic structure calculations, which form the basis for the classification of materials into conductors, semiconductors or insulators. DFT started with a crude approximation by Thomas and Fermi (TF theory) which calculated the kinetic energy of electrons using the so-called local density approximation (LDA). Although TF is computationally inexpensive, it provides a poor numerical result due to a lack of understanding of the density dependence of the kinetic energy. Another approximation to the kinetic energy is the von-Weizsacker (vW) term, which greatly improves the TF theory, yet the full functional form of the kinetic energy remains unknown. We seek to develop a supplemental term to the kinetic energy density functional and compute corrections to the Thomas-Fermi-von-Weizsacker kinetic energy of closed shell atoms in order to improve its accuracy.