radtools.MagnonDispersion.J

method

MagnonDispersion.J(k)

Computes J(k) matrix.

\[\boldsymbol{J}_{i,j}(\boldsymbol{k}) = \sum_{\boldsymbol{d}}\boldsymbol{J}_{i,j}(\boldsymbol{d})e^{-i\boldsymbol{k}\boldsymbol{d}}\]

where indices \(i\) and \(j\) correspond to the atoms in the exchange pair.

Parameters:

k(3,) array-like

Reciprocal vector. In absolute coordinates.