  Modifications to the quasiparticle self-consistent GW (QSGW) method needed to
correctly describe metal/vacuum interfaces and other systems having extended
regions with small electron density are identified and implemented. The
method's accuracy is investigated by calculating work functions for the
Al(111), Al(100), and Al(110) surfaces. We find that the results for work
function do not depend on the DFT functional employed to calculate the starting
Hamiltonian and that QSGW yield results in quantitative agreement with data
from ultrahigh vacuum experiments.
