To use the MIC in the solution of the induced dipoles, only the electric fields from the permanent multipoles and induced dipoles need to be modified. The fields from the nuclei and electrons are unchanged because the quantum subsystem is centered in the simulation box. The electric field from a set of (permanent or induced) multipoles involves derivatives of the inverse distance between the classical sites. These can be conveniently expressed as interaction tensors that can be defined generally using a multi-index notation