Periodic boundary conditions allow self interactions in 2D #115
Description
When a 2D film in the xy-plane is specified in a config file and periodic boundaries are True for all directions, the exchange Hamiltonian doesn't flag that this may be an issue if a single exchange bond in the z-direction is specified. It correctly identifies an problem when both the interaction along +z and -z are specified.
It is probable this will also be the case for a 1D chain in both transverse directions.
config.txt