  This note summarizes the motivation for extending current density-functional
theory to include nonlocal one-electron potentials, and proposes methodology
for practical calculations. The theoretical model, orbital functional theory,
has been shown to be exact in principle for the general N-electron problem, but
must depend in practice on a parametrized correlation energy functional. The
discussion here is intended to honor Lee Allen and to bring up to date some
conversations that we began in 1954.
