We show with an ab initio calculation that electronic surface states have a
strong effect on NMR chemical-shift spectra. For the hydrogen-chemisorbed
diamond (111) surface, we find that the atomic layers close to the surface
experience a variation of the chemical shift, which is proportional to the
density of empty surface states. This effect could be used as a direct prob
e of the surface-state density profile, by measuring experimentally the NMR
chemical shift resolved for each atomic layer. [S0163-1829(99)00523-8].