Ab initio theoretical calculations of the electronic excitation energies of small water clusters

作者：Tachikawa Hiroto^*; Yabushita Akihiro; Kawasaki Masahiro

来源：Physical Chemistry Chemical Physics, 2011, 13(46): 20745-20749.

DOI：10.1039/c1cp20649d

A direct ab initio molecular dynamics method has been applied to a water monomer and water clusters (H(2)O)(n) (n = 1-3) to elucidate the effects of zero-point energy (ZPE) vibration on the absorption spectra of water clusters. Static ab initio calculations without ZPE showed that the first electronic transitions of (H(2)O)(n), (1)B(1) <- (1)A(1), are blue-shifted as a function of cluster size (n): 7.38 eV (n = 1), 7.58 eV (n = 2) and 8.01 eV (n = 3). The inclusion of the ZPE vibration strongly affects the excitation energies of a water dimer, and a long red-tail appears in the range of 6.42-6.90 eV due to the structural flexibility of a water dimer. The ultraviolet photodissociation of water clusters and water ice surfaces is relevant to these results.

• 出版日期2011