WHAT IS THE STRUCTURE OF FEC5H6+

Calculations performed using both density functional theory (DFT) and the modified coupled-pair functional (MCPF) approach show that FeC5H6 is more stable than HFeC5H5+ by about 10 kcal/mol. The ground state o f FeC5H6+ is a quartet state derived from the 3d(7) occupation of Fe+. For HFeC5H5+, the MCPF approach yields a sextet ground state while DF T yields a quartet; however, these two states are close in energy at b oth levels of theory.