Abstract

Discovery of the "divine" exchange-correlation energy functional in density functional theory (DFT), both universally accurate and readily computable, remains an elusive goal. Recently, a new strategy, the subsystem functional scheme, has been formulated to improve calculations based on DFT. This scheme divides a system into physically distinct subsystems and applies different, targeted approximations for the functional to the different subsystems. For example, using one functional in the interior region of a system, and another in the exterior surface region where the density decays to zero. In this talk I will present the fundamentals of subsystem functionals and give examples on how even crude application of these ideas can improve DFT results for real systems. Specifically I will discuss results for the work of adhesion of Pd(111) to alpha-alumina and monovacancy formation energies for Pd, Pt, Mo, and Al.

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.