Numerous studies The structure of the paper is as follows. In the next section, we provide an overview of the EOM-CC theory and Bloch's formalism. We then apply Bloch's formalism to the EOM-CC wave functions and derive the working expressions. Next, we consider several molecules for which we discuss Hubbard's and Heisenberg's Hamiltonians rigorously constructed from the EOM-SF-CCSD solutions. Whenever possible, we compare the results from extraction through the Landé rule and from the effective Hamiltonians.