In this section, we present VFCI results for the low energy spectra of Si 2e-DQD devices with parameters similar to those of actual quantum qubits investigated experimentally and reported in recent and current literature. Prior to presentation and discussion of the results of our calculations, it is pertinent to comment here in some detail about certain aspects of our calculations, originating from the intrinsic properties of the material (silicon) used in making the DQD qubits addressed by our study.