Wavefunction

Wavefunction in SJB Slater-Jastrow-backflow form is represented by the casino.Wfn class.

\[\Psi(\mathbf{r}) = e^{J(\mathbf{r})}\Phi(\mathbf{r} - \xi(\mathbf{r}))\]

where \(\xi(\mathbf{r})\) is the backflow displacement of electrons, which depends on the configuration of the whole system.