Energy level shifts of CO chemisorbed and condensed on RH(111)

Energy level shifts of CO in different phases, gas, solid and chemisorbed on Rh(111) are compared. Between gaseous and solid CO a shift of the 4σ and 5σ derived molecular orbitals of about 2.7 eV to lower binding energies due to polarization is observed. A larger 1π – 4σ separation of the CO molecules condensed and chemisorbed on Rh(111) is observed with respect to the gas phase. A comparison of the binding energies of the three molecular orbitals in the different phases allows to estimate the bonding shift of the 5σ level to 2.7 eV.