Theoretical studies of the water-cluster anions containing the OH{e}HO structure: energies and harmonic frequencies

In addition to isomers having a dipole-bound electron, the internally bound electron isomers of trimer, tetramer and hexamer water anions are found us ing an ab initio molecular orbital method. The latter isomers have a charac teristic OH{e}HO structure. The interaction between the excess electron P{e } and the surrounding OH bonds holds the structure stable. The calculated v ibrational infrared spectrum for a hexamer anion with two double proton-acc eptor water molecules shows a qualitatively similar vibrational spectrum wi th the one observed. A strong correlation between the vertical detachment e nergy and the distribution of the excess electron is also found. (C) 2000 E lsevier Science B.V. All rights reserved.