Density functional theory (DFT) is increasingly popular as a tool for determining the electronic structure of molecules and materials.  The foundation of the approach is the existence of a universal and exact functional map between the ground-state density and the exact ground-state energy.  The limitations of the method lie in the lack of a systematic means of constructing this functional theoretically, compounded by the lack of direct experimental means to determine it.  One possible way around these limitations is the use of computational simulations using many-body method

 In this talk, I will explain how non-equilibrium Green’s
function (NEGF) approach combined with density functional theory (DFT)
compute transport properties of molecular junctions. In the first
part, successes and failures of local and semi-local density
functionals are discussed, and an inexpensive, GW-based correction,
known as DFT+Sigma, is reviewed. The method is applied to complicated
systems involving transition metals, where semi-local functionals fail
qualitatively. In the second part, a method to compute molecular