Hydrogen dissociation on small aluminum clusters

摘要: Transition states and reaction paths for a hydrogen molecule dissociating on small aluminum clusters have been calculated using density functional theory. The two lowest spin taken into account all the Al(n) considered, with n=2-6. dimer, which shows (3)Π(u) electronic ground state, has also studied at coupled cluster configuration interaction level comparison to check accuracy of single determinant calculations in this special case, where degenerate configurations should be account. barriers give an explanation experimentally observed reactivity Al different size [Cox et al., J. Chem. Phys. 84, 4651 (1986)] reproduce high Al(6) cluster. structure Al(n)-H(2) systems was systematically investigated order determine role played by interactions specific molecular orbitals nuclear arrangements. Singlet (with n even) exhibit H(2) dissociation because their highest doubly occupied allow more favorable antibonding σ(u) orbital H(2).