TY - JOUR
T1 - Anionic water clusters with large vertical electron binding energies and their electronic spectra
T2 - (H2O)11- and (H2O)14-
AU - Sobolewski, Andrzej L.
AU - Domcke, Wolfgang
PY - 2003/3/15
Y1 - 2003/3/15
N2 - The structures of four isomers of both (H2O)11- and (H2O)14- cluster anions have been determined by geometry optimization at the ROHF level. These structures exhibit vertical electron binding energies of the order of 0.4-0.6 eV and 0.8-1.0 eV for (H2O)11- and (H2O)14-, respectively, in satisfactory agreement with the maxima of the experimental photodetachment spectra. Three of the structures contain a H3O+-OH- ion pair; the others consist of nondissociated water molecules with maximally aligned dipole moments. The dipole moments of the corresponding neutral clusters are significant (12-18 Debye for (H2O)11, 18-24 Debye for (H2O)14). The excess electron in these cluster anions is a so-called surface electron, i.e., it resides outside the water hydrogen-bond network. The vertical excitation energies and oscillator strengths of these cluster anions have been calculated with the TDDFT method. All cluster anions exhibit a strong low-energy absorption band corresponding to the 3s → 3p transition of the excess electron. The peak of this absorption band is found between 0.55 and 0.75 eV for (H2O)11- and between 0.77 and 0.95 eV for (H2O)14-, in good agreement with the experimental estimates of 0.70 eV and 0.79 eV for (H2O)11- and (H2O)14-, respectively.
AB - The structures of four isomers of both (H2O)11- and (H2O)14- cluster anions have been determined by geometry optimization at the ROHF level. These structures exhibit vertical electron binding energies of the order of 0.4-0.6 eV and 0.8-1.0 eV for (H2O)11- and (H2O)14-, respectively, in satisfactory agreement with the maxima of the experimental photodetachment spectra. Three of the structures contain a H3O+-OH- ion pair; the others consist of nondissociated water molecules with maximally aligned dipole moments. The dipole moments of the corresponding neutral clusters are significant (12-18 Debye for (H2O)11, 18-24 Debye for (H2O)14). The excess electron in these cluster anions is a so-called surface electron, i.e., it resides outside the water hydrogen-bond network. The vertical excitation energies and oscillator strengths of these cluster anions have been calculated with the TDDFT method. All cluster anions exhibit a strong low-energy absorption band corresponding to the 3s → 3p transition of the excess electron. The peak of this absorption band is found between 0.55 and 0.75 eV for (H2O)11- and between 0.77 and 0.95 eV for (H2O)14-, in good agreement with the experimental estimates of 0.70 eV and 0.79 eV for (H2O)11- and (H2O)14-, respectively.
UR - http://www.scopus.com/inward/record.url?scp=0037444343&partnerID=8YFLogxK
U2 - 10.1039/b211893a
DO - 10.1039/b211893a
M3 - Article
AN - SCOPUS:0037444343
SN - 1463-9076
VL - 5
SP - 1130
EP - 1136
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 6
ER -