  A scattering method is used to calculate the surface band structure of
Al(111) from 8.6 eV below the Fermi level to 9 eV above it. This method has
rarely been implemented previously. The complete complex bulk and surface band
structure is also shown for key values of the crystal surface-parallel
momentum. The surface region is treated semi-empirically from a small number of
experimentally determined quantities. We find agreement over the whole surface
Brillouin zone for surface states compared with recent theoretical ab initio
results and experiment. Differences with respect to surface resonances detected
by recent theoretical methods are discussed. In particular a class of surface
resonances is detected here that may be surface-layer localised and results
from very wide partial surface-projected energy gaps where real lines in the
complex bulk band structure extend from band minima to infinity. Other methods
do not appear to have detected these resonances. They may have an effect on
photoemission intensity profiles and may account for previous unexplained
experiment features considered to be "a kind of surface enhancement at partial
gap edges". This scattering method provides a single picture for the formation
and classification of surface states and resonances.
