  The nitrogen vacancy (NV) center in diamond is a sensitive probe of magnetic
field and a promising qubit candidate for quantum information processing. The
performance of many NV-based devices improves by aligning the NV(s) parallel to
a single crystallographic direction. Using ab initio theoretical techniques, we
show that NV orientation can be controlled by high-temperature annealing in the
presence of strain under currently accessible experimental conditions. We find
that $(89\pm7)\%$ of NVs align along the [111] crystallographic direction under
2\% compressive biaxial strain (perpendicular to [111]) and an annealing
temperature of 970$^\circ$C.
