Hi,
I'm using Siesta to calculate band structure of bulk gold. It's expected to
find one relative band gap (in which fermi level lies. PS: this gap
supports an occupied Shockley surface state) along GL line (corresponding
to [111] direction) in reciprocal space. I did find one when setting the
cell size to 1x1x1 (primitive cell containing only one atom), but failed
when setting cell size to 2x2x2 (primitive cell containing 8 atoms), see
the attachment for detail. I don't quite understand why the relative gap
vanish near fermi level, one consequence of which seems to be the
disappearance of the previously-mentioned Shockley surface state. Can
anyone explain this?
