Chemisorption of uracil on gold surfaces via density functional theory

We have performed a periodic density functional theory study, including a correction for the dispersive forces (DFT-D), of the adsorption of the pyrimidine nucleobase uracil on the Au(100) and Au(111) surfaces. We illustrate the influence of the inclusion of dispersive interactions in the calculation on the geometries and energetics of adsorption. A systematic analysis has been undertaken on both surfaces, where we have explored two possible deprotonation of the two nitrogen positions of the uracil and compared the core-level binding energies of the chemisorbed phase with previous experimental findings and calculations.