Density Matrix Embedding Theory (DMET) is another method that utilises fragment embedding to estimate the wavefunction and the energy of a molecule. The main difference between DMET and BE is the matching condition. Since DMET normally uses non-overlapping fragments, it aligns the density matrix of the mean field with that of the correlated wavefunction computation for each fragment. On the other hand, BE utilises overlapping fragments and aligns the density matrix of one fragment with that of another within their shared region of overlap. Therefore, matching in BE can be expressed mathematically as a collectively restricted optimisation problem. To briefly describe how this is done, consider two overlapping fragments, A and B, which is shown in Figure . min