Application of long-range corrected density-functional theory to excess electron attachment to biomolecules

The knowledge of excess electron binding mechanisms in biomolecules is very important for molecular-level understanding of DNA damage by low-energy electrons. We here focus on two different excess electron binding mechanisms from the theoretical side; diffuse dipole-bound and valence-bound anionic states. We have found that long-range corrected (LC) density-functional theory (DFT) methods combined with a set of diffuse basis functions can reasonably describe electronic transformation processes between these two different anionic states. The applicability of the LC-DFT calculations is demonstrated for uracil, guanine–cytosine base pair, fructose, and uracil-iodide anion complex.