| Abstract
| - A combined electronic structure/molecular dynamics approach was used to calculate infrared and isotropicRaman spectra for the OH or OD stretches of dilute HOD in D2O or H2O, respectively. The quantities neededto compute the infrared and Raman spectra were obtained from density functional theory calculations performedon clusters, generated from liquid-state configurations, containing an HOD molecule along with 4−9 solventwater molecules. The frequency, transition dipole, and isotropic transition polarizability were each empiricallyrelated to the electric field due to the solvent along the OH (or OD) bond, calculated on the H (or D) atomof interest. The frequency and transition dipole moment of the OH (or OD) stretch of the HOD moleculewere found to be very sensitive to its instantaneous solvent environment, as opposed to the isotropic transitionpolarizability, which was found to be relatively insensitive to environment. Infrared and isotropic Ramanspectra were computed within a molecular dynamics simulation by using the empirical relationships andsemiclassical expressions for the line shapes. The line shapes agree well with experiment over a temperaturerange from 10 to 90 °C.
|
