Density functional theory for systems of very many atoms

The standard Kohn‐Sham formulation of density functional theory ( DFT ) is limited, for practical reasons, to systems of less than about 50‐100 atoms. The computational effort scales as N   at α , where N at is the number of atoms and 2 < α > 3. (By comparison, conventional configuration interaction methods are limited to 5‐10 atom systems.) This article deals with the prospect of practical methods that scale linearly in N at and may thus allow calculations for systems of 10 3 ‐104 atoms. The physical reason (“near‐sightedness”) for linear scaling is presented. Implementations of linear scaling DFT by the use of generalized Wannier functions or the one‐particle density matrix are discussed. © 1995 John Wiley & Sons, Inc.