The computation of the MI index I ij involves the expectation value of a variety of n-body operators O pkq i listed in Refs. from which the orbital-RDMs can be determined. These orbital-RDMs can be further resolved using up to 4-particle RDMs . Whereas high-quality RDMs or, eventually, orbital-RDMs can be constructed from sophisticated electronic structure theories, such as DMRG, this is not practical when going towards extensive systems. For this reason, we will investigate the effectiveness of lower-quality wavefunctions based on single-particle assumptions, i.e., mean-field solutions, like Hartree-Fock theory or Kohn-Sham Density Functional Theory (KS-DFT), and validate the results against expensive DMRG results for smaller peptide systems. The benefit of employing Slater determinant wavefunctions is the existence and applicability of Wick's theorem , significantly reducing the computation cost of n-body operator expectation values. An example of Wick's theorem at work is provided in Appendix A.1. The obvious price to pay for this simplification is that it does not apply to multi-reference systems with strong quantum correlations, such as transition metal compounds. However, our ultimate focus is to verify the locality of quantum correlations in extensive organic systems, for which self-consistent field methods have proven to provide sufficiently accurate results for different purposes .