Field-induced vibrational frequency shifts of CO and CN chemisorbed on Cu(100)

Analysis of ab initio cluster wave functions show that the shifts in the vibrational frequencies of CO/Cu and CN/Cu due to an applied electric field arise dominantly from a Stark effect. The CN bonding is largely ionic while CO has a dative covalent bond. Consequently the Stark effect mechanisms are significantly different. © 1987 The American Physical Society.