  We present a detailed analysis of the role of native point defects in the
antiferromagnetic (AFM) phases of bulk chromium nitride (CrN). We perform
first-principles calculations using local spin-density approximation, including
local interaction effects (LSDA+U), to study the two lowest energy AFM models
expected to describe the low-temperature phase of the material. We study the
formation energies, lattice deformations and electronic and magnetic structure
introduced by native point defects. We find that, as expected, nitrogen
vacancies are the most likely defect present in the material at low
temperatures. Nitrogen vacancies present different charged states in the cubic
AFM model, exhibiting two transition energies, which could be measurable by
thermometry experiments and could help identify the AFM structure in a sample.
These vacancies also result in partial spin polarization of the induced
impurity band, which would have interesting consequences in transport
experiments. Other point defects have also signature electronic and magnetic
structure that could be identified in scanning probe experiments.
