EFFICIENT ITERATIVE DIAGONALIZATION OF SEPARABLE PSEUDOPOTENTIAL HAMILTONIANS

Iterative diagonalization techniques as well as Car-Parrinello molecular dynamics simulation using first principles pseudopotentials require the repeated calculation of matrix times vector products. We discuss a technique which reduces the number of operations for the separable part of the Hamiltonian expressed in plane waves from order NN(at)N(el) to order N ln (N)N(el) where N is the number of plane waves, N(at) the number of atoms, and N(el) the number of electrons.