A First Principles Study of the Adsorption and Dissociation of CO$_{2}$ on the $\delta $-Pu (111) Surface~

\textit{Ab initio} calculations within the framework of density functional theory have been used to study the adsorption of molecular CO$_{2}$ and the corresponding partially dissociated (CO+O) and completely dissociated (C+O+O) products on the $\delta $-Pu (111) surface. The completely dissociated C+O+O configurations exhibit the strongest binding with the surface (5.85 eV), followed by partially dissociated products CO+O (4.34 eV), with molecular CO$_{2}$ adsorption having the lowest binding energies (2.98 eV). For all initial vertically upright orientations the CO$_{2}$ molecule is physisorbed and its geometry and orientation does not change. For all initial flat lying orientations chemisorption occurs, with the final state corresponding to a bent CO$_{2}$ molecule with bond angles of 118$^{o}$-130$^{o}$ except one case where spontaneous partial dissociation from the atop site occurs. The interactions of the CO$_{2}$ and CO with the Pu surface have been analyzed using the energy density of states and difference charge density distributions.