Path-integral molecular dynamics simulations for water anion clusters and

Quantum path-integral molecular dynamics simulations have been performed for the ( H 2 O ) 5 - and ( D 2 O ) 5 - anion clusters on the basis of a semiempirical one-electron pseudopotential-polarization model. Due to larger zero-point vibrational amplitudes for H atoms than that of D atoms, hydrogen-bond lengths in the ( H 2 O ) 5 - cluster are slightly larger than those in ( D 2 O ) 5 - . The distribution of the vertical detachment energies for ( H 2 O ) 5 - also show a broader feature than that for ( D 2 O ) 5 - . The present PIMD simulations thus demonstrate the importance of nuclear quantum effects in water anion clusters.