Example

A square lattice : La₂CuO₄

This is the J1-J2 square lattice of S = 1/2 spins characterising La₂CuO₄.

In the illustration below is represented the corresponding dispersion relation, along high symmetry directions of the 2D Brillouin zone, calculated with J1 = 111.8 meV and J2= -11.4 meV (according to R. Coldea et al., Phys. Rev. Letters 86, 5377 (2001)).

The input file corresponding to this case can be found in the download package.