A DRUDE MODEL APPROACH TO DISPERSION INTERACTIONS IN DIPOLE-BOUND ANIONS

摘要

The problem of the binding of an excess electron to polar molecules and their clusters with sufficient attractive electrostatic potential has long fascinated researchers. Although excess electrons bound to such attractive potential tend to be very extended spatially and to have little spatial overlap with the valence electrons of the neutral molecules, inclusion of electron correlation effects is essential for quantitatively describing the electron binding. The major electron correlation contribution may be viewed as a dispersion interaction between the excess electron and the electrons of the molecule or cluster. Intrigued by the success of classical Drude model treatment of neutral atoms or molecules, a new one-electron model based on Drude oscillator was introduced, and its application on HCN-, (HCN)2-, HNC-, (HNC)2- and (H2O)n- was studied. The newly developed water potential is used in carrying out parallel-tempering Monte-Carlo simulations of the (H2O)6- cluster.