surface green's function in an arbitrary direction

[apezol]

Dear developers, I haven't check properly this, but from 'tile' option it seems to me that it's possible to replicate the system's periodicity in any of the three directions given by the lattice vectors, would it be possible to do the same for any arbitrary direction?, if so, can the surface green's function method can be adapted to calculate either surface band structures or even any other property that can exploit extrapolated properties from the bulk?...this can give direct information for studying edge or surface states without the need of considering large supercells. I know that the surface Green's functions are used for the NEGF so if the crystallographic directions are provided won't be hard to adapt it right?,

[zerothi]

That's actually not so easy. The surface Green's function depends on a well-defined direction.

And for extending a unit-cell along an arbitrary direction is not trivial...

The reason is that you want a coupling matrix along the semi-infinite direction, and hence you would have to re-create the unit-cell with a lattice vector along that respective direction. i don't know if there are work-arounds. Insights would be helpful!