Pseudoptential theory of shallow-donor ground states. II

A pseudopotential calculation is done for the ground states of the shallow donors N, P, As, Sb, and Bi in Si. The pseudopotential is screened linearly. Good results are obtained for As, the one impurity for which the size effect is small. It is argued that deformation of the lattice cannot account for the size effect. However, accounting for the size effect by compressing the impurity core gives wave functions for which the calculated values of ${\left|\Psi \mathrm{}\right(0\left)\right|}^2$ agree well with experiment. In addition, most of the electron-nuclear-double-resonance lines are identified for P, As, and Sb impurities.