  For a next-nearest neighbour pair interaction model in a periodic domain, a
priori and a posteriori analyses of the quasinonlocal quasicontinuum method
(QNL-QC) are presented. The results are valid for large deformations and
essentially guarantee a one-to-one correspondence between atomistic solutions
and QNL-QC solutions. The analysis is based on truncation error and residual
estimates in negative norms and novel a priori and a posteriori stability
estimates.
