Electron binding energies in linear dipole-bound (HCN)(n)(-) (n=2-5) anions

The (HCN)(2)(-) anion has been studied at the coupled cluster level of theo ry with single, double, and non-iterative triple excitations whereas equili brium structures and electron binding energies for larger linear (HCN)(n)(- ) (n = 3-5) clusters have been determined at the second-order Moller-Plesse t (MP2) level. The adiabatic electron affinity of (HCN)(2) was found to be 399 cm(-1) and trends in physically meaningful components of electron bindi ng energy, such as static Coulomb, dispersion, and polarization stabilizati ons, were determined for this series of clusters. The (2)Pi dipole-bound an ionic state was found for the pentamer with the MP2 vertical electron detac hment energy of 92 cm(-1). (C) 1999 Elsevier Science B.V. All rights reserv ed.