(3, 1) terms

First type of the trilinear terms, in which all three spin operators are associated with the same site.

\[\begin{split}C_{3,1} \sum_{\substack{\mu, \\ \alpha_1, \\ i_1, i_2, i_3}} J^{i_1, i_2, i_3}_{0; \alpha_1, \alpha_1, \alpha_1} S_{\mu, \alpha_1}^{i_1} S_{\mu, \alpha_1}^{i_2} S_{\mu, \alpha_1}^{i_3}\end{split}\]

Relevant API

• magnopy.Convention.c31

  Convention constant.

• magnopy.SpinHamiltonian.add()

  Method to add the parameter to the Hamiltonian.

• magnopy.SpinHamiltonian.remove()

  Method to remove the parameter from the Hamiltonian.

• magnopy.SpinHamiltonian.p31

  An iterator over the parameters already added to the Hamiltonian.