the electrode relax issue

[njuxyh]

i am reading the tutorial named "ATK Tutorial for Device Configurations",
one question came from there, that is about optimize the electrodes,
my electrode is a cleaved metal surface, Au (111),  according to the tutorial, i should optimize it, but i read some references, they did not relax it, for example  http://http://scitation.aip.org/content/aip/journal/jcp/123/11/10.1063/1.1993558, i.e. , keep the bond length of Au to be the experimental bulk bond length.

so, i don not know whether it is necessary to optimize the elelctrode Au (111),

i need your help, thanks

 

[Anders Blom]

You should, in principle, relax it, but if I remember correctly the LDA or PBE predicted structure is very close to the experimental one.