  Very few works exist to date on development of a consistent energy-based
coupling of atomistic and continuum models of materials in more than one
dimension. The difficulty in constructing such a coupling consists in defining
a coupled energy whose minimizers are free from uncontrollable errors on the
atomistic/continuum interface. In this paper a consistent coupling in three
dimensions is proposed. The main achievement of this work is to identify and
efficiently treat a modified Cauchy-Born continuum model which can be coupled
to the exact atomistic model. The convergence and stability of the method is
confirmed with numerical tests.
