An efficient preconditioning scheme for plane-wave-based electronic structure calculations

We propose a preconditioning scheme for diagonalizing large Hamiltonian mat rices arising in first-principles planewave pseudopotential calculations. T he new scheme is based on the Neumann expansion for the inverse, shifted Ha miltonian from which only a nonlocal part is omitted. The preconditioner is applied to a gradient vector using the fast Fourier transformation techniq ue. In the framework of the Davidson-type diagonalization algorithm, we hav e found the present preconditioning scheme to be more efficient than widely accepted diagonal scaling methods. (C) 1999 Published by Elsevier Science B.V. All rights reserved.