If i want to find the band structure of a material in nano scale what should i do?

I can create a 3D atomistic document and i can build or import a structure and optimize its geometry and I can find band structures.

1. But i dont know does it corresponds to bulk band structure or not?

2. I want to calculate the band structure for a nano particle of specific size and morphology say a sperical poly crystalline quantum dot. What changes i should be careful to do?

Thanks,

Balaji.V