pythtb.Wannier.spread

property Wannier.spread

Quadratic spread for each Wannier function.

\[\Omega_n = \langle \mathbf{0} n | r^2 | \mathbf{0} n \rangle - \langle \mathbf{0} n | \mathbf{r} | \mathbf{0} n \rangle^2\]

where \(|\mathbf{0} n\rangle\) are the Wannier functions in the home unit cell and \(\Omega = \sum_n \Omega_n\) is the total spread.