  We present a study of the effects of Nitrogen and Boron doping on the growth
of CVD diamond in the (100) mechanism. These are the first calculations of this
type and show that, in accordance with recent experimental results, the
presently accepted growth mechanism, that due to Harris, is cataylsed by the
presence of subsurface Boron impurities. In contrast, we find that the Harris
Mechanism cannot explain growth in the presence of subsurface N and suggest an
alternative mechanism.
