[Wien] Cu(111) Surface State

[Chiung-Yuan Lin]

Dear all,
  I was doing slab calculation for Cu(111). From experiments, there is
a surface state 0.39eV below the Fermi energy. I did 5-layer, 7-layer,
and 21-layer slabs (with 4, 8, and 8 layers of vaccum respectively).
The calculated surface states are 0.3, 0.44, and 0.54 eV respectively.
The charge convergence criterions are 0.01, 0.01, and 0.005 respectively.
All 3 cases are calculated using the potential option PBE96. I am
wondering if those calculated energies are the best Wien2k can do.
  A previous question was discussed between Stolbov and Prof Blaha
(in the "new digest", 2003 December, "Plotting surface potential").