We discuss the construction of quasi-optimal energy based atomistic/continuum (A/C) coupling methods for crystalline solids with defects, based on tools from numerical analysis. For general multi-body interactions on the 2D triangular lattice (and potentially for 3D lattices), we show that ghost force removal (patch test consistent) A/C methods can be constructed for arbitrary interface geometries. We prove that all methods within this class are first-order consistent at the atomistic/continuum interface. The rigorous error analysis of the coupling methods leads to their optimal implementation. For a range of benchmark problems, the resulting consistent coupling methods have the same convergence rates as optimal force-based coupling schemes. This is a joint work with Christoph Ortner (Warwick).