  Auxiliary-field quantum Monte Carlo (AFQMC) has repeatedly demonstrated
itself as one of the most accurate quantum many-body methods, capable of
simulating both real and model systems. In this article we investigate the
application of AFQMC to realistic strongly correlated materials in periodic
Gaussian basis sets. Using nickel oxide (NiO) as an example, we investigate the
importance of finite size effects and basis set errors on the structural
properties of the correlated solid. We provide benchmark calculations for NiO
and compare our results to both experiment measurements and existing
theoretical methods. (LLNL-JRNL-752156)
