Surface reconstructions of lattices

[jaejoon89]

Why does gold have a surface reconstruction but graphite does not?

The Au(111) crystal, when cut, reorganizes at the surface to minimize tensile stress and energy. Why doesn't graphite do this?

 

[chemisttree]

What type of bonding is there in a sheet of graphite? What type is there in the gold [1,1,1] crystal? Is thermal energy (RT?) enough to overcome both or only one?

 

[jaejoon89]

Bonding in graphite would be sigma bonds, plus delocalized pi bonds... I'm not sure about gold (1,1,1). The electron configuration for Au is [Xe] 4f14 5d10 6s1 so the s orbitals rather than the d orbitals participate in bonding - right? - so they form sigma bonds only? Or do you use a different model for transition metal elements? I'm really not sure how to think about this...