First principles determinations of the bonding mechanism and adsorption energy for CO/MgO(001)

Using the highly precise local density functional full potential linearized augmented plane wave (FLAPW) method, we have studied the bonding mechanism and other electronic properties of CO physisorption on the MgO(001) substrate. The calculated adsorption energy and the blue shift of the CO stretch frequency are 0.28 eV/molecule and 33 cm−1, in good agreement with the corresponding experimental data of 0.3–0.43 eV/molecule and 35 cm−1, respectively. The charge density contours indicate that a significant charge redistribution (bonding) is involved in the CO/MgO(001) interaction, in contrast with previous cluster calculations which suggested that the CO–MgO interaction is of the Van der Waals type.