DESIGN OF AN EXCHANGE FUNCTIONAL WITH CORRECT ASYMPTOTICS

摘要

Knowledge of asymptotic conditions on exchange allows for a better design of exchange energy expressions in density functional theory. By working inside an exchange-only framework, the fulfillment of such conditions by some of the most widely used exchange functionals is discussed. In turn, we propose a model expression which partially meets the energetics and asymptotics of both the exchange energy density and potential. Improvement upon the local spin density approximation without the use of generalized gradient corrections is also presented. Hartree-Fock orbitals are employed to build electron densities. (C) 1997 John Wiley & Sons, Inc. [References: 13]