- #1
R Van Camp
- 8
- 0
We recently covered the tight binding model. I have a question from an early lecture regarding sign conventions for the hopping parameter t(T). It was explained that t>0 due to MO theory. I agree and understand why; orbital overlap. It was then stated that tnn<0; that is, tnn=-t.
I am not following why tnn<0. It makes some sense that this is true in view of the increase in charge delocalization associated with any mode of hopping. Ultimately, I am looking to understand the physical significance of the sign of tnn, tnnn, etc.
I am not following why tnn<0. It makes some sense that this is true in view of the increase in charge delocalization associated with any mode of hopping. Ultimately, I am looking to understand the physical significance of the sign of tnn, tnnn, etc.