Use the Zeroth Order Hamiltonian node to include additional zeroth order Hamiltonian terms. Also see the comment about the built-in factor in Second Order Hamiltonian (Equation 5-1).

In the Hamiltonian input table, use the drop down menus to enter the Hamiltonian row index (m) and Hamiltonian column index (n). Use the input fields to enter the Zeroth order Hamiltonian parameter (Unit: 1/m^2) and the Description.