# Can I get Bandgap of 3D material with 1D Hamiltonian

1. Feb 18, 2014

### Arya_

Hi All,

Greetings!

I have a 3d material and I use result from first principal for getting the potential (U(x,y,z)). I then find average U(x) from U(x,y,z). Now if I write one dimensional Hamiltonian in X direction and use this value of U(x), can I get bandgap of the original 3d material (I am not interested to see the bandstructure, bandgap is what I need)

Thanks,
_Arya

2. Feb 19, 2014

### cgk

No. Why do you think this should be possible? A one-dimensional chain of something is a completely different physical system than a 3d bulk material. (And that is not even considering the /massive/ approximations in what I can only guess you are doing)