  Modeling charge transport in DNA is essential to understand and control the
electrical properties and develop DNA-based nanoelectronics. DNA is a
fluctuating molecule that exists in a solvent environment, which makes the
electron susceptible to decoherence. While knowledge of the Hamiltonian
responsible for decoherence will provide a microscopic description, the
interactions are complex and methods to calculate decoherence are unclear. One
prominent phenomenological model to include decoherence is through fictitious
probes that depend on spatially variant scattering rates. However, the built-in
energy-independence of the decoherence (E-indep) model overestimates the
transmission in the bandgap and washes out distinct features inside the valence
or conduction bands. In this study, we introduce a related model where the
decoherence rate is energy-dependent (E-dep). This decoherence rate is maximum
at energy levels and decays away from these energies. Our results show that the
E-dep model allows for exponential transmission decay with the DNA length and
maintains features within the bands' transmission spectra. We further
demonstrate that we can obtain DNA conductance values within the experimental
range. The new model can help study and design nanoelectronics devices that
utilize weakly-coupled molecular structures such as DNA.
