The structural and electronic properties of column V acceptor impuriti
es in ZnSe are reviewed with special emphasis on N. The results of our
calculations indicate that As and P acceptors possess two atomic conf
igurations: a metastable effective-mass state with a small lattice rel
axation and a stable deep state with a large lattice relaxation. Subst
itutional N gives rise to shallow acceptor states in either configurat
ion. The low 20-30% doping efficiency is proposed to be caused by N bo
nding at interstitial sites. Various interstitial bonding configuratio
ns are found to give both shallow donor and shallow acceptor states le
ading to self-compensation. Post growth in diffusion of N is proposed
to be useful in increasing the concentration of shallow acceptor state
s.