Sequential classical-quantum description of the absorption spectrum of the hydrated electron

A localized state of the electron in water is assumed to study the absorption spectrum of the hydrated electron. A classical Monte Carlo statistical mechanics simulation is used to generate the structure of water in the field of the hydrated electron. These structures are used in quantum mechanical calculations of the absorption spectrum using time-dependent density-functional theory. The statistically converged spectral distribution is in good agreement with experiment. The value obtained here for the maximum of the absorption profile is $1.70\mathrm{eV}$ with a half-width of $0.90\mathrm{eV}$, in comparison with the corresponding experimental values of 1.725 and $0.84\mathrm{eV}$.

Figure 1

Classical pairwise radial distribution function between the center of the electron charge distribution and the center of mass of the water molecules.

Figure 2

Illustration of the molecular orbital of the excess electron. (a) and (b) are Kohn-Sham and Hartree-Fock orbitals using the same configuration of the first hydration shell, respectively. (c) and (d) are the same for the second hydration shell.

Figure 3

Statistical convergence of the average transition wave number for the first hydration shell.

Figure 4

Comparison between the theoretical and experimental (Ref. 3) profiles of the optical absorption spectrum.