Quantum path-integral molecular dynamics simulations have been performed for the (H2O)(5)(-) and (D2O)(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 (H2O)(5)(-) cluster are slightly larger than those in (D2O)(5)(-). The distribution of the vertical detachment energies for (H2O)(5)(-) also show a broader feature than that for (H2O)(5)(-). The present PIMD simulations thus demonstrate the importance of nuclear quantum effects in water anion clusters. (C) 2009 Elsevier B. V. All rights reserved.