  For a general class of atomistic-to-continuum coupling methods, coupling
multi-body interatomic potentials with a P1-finite element discretisation of
Cauchy--Born nonlinear elasticity, this paper adresses the question whether
patch test consistency (or, absence of ghost forces) implies a first-order
error estimate.
  In two dimensions it is shown that this is indeed true under the following
additional technical assumptions: (i) an energy consistency condition, (ii)
locality of the interface correction, (iii) volumetric scaling of the interface
correction, and (iv) connectedness of the atomistic region. The extent to which
these assumptions are necessary is discussed in detail.
