Hyperpolarizability of the neon atom

Abstract

The multiconfiguration time-dependent Hartree-Fock method is applied to compute the hyperpolarizabiltiy of the neon atom and its frequency dependence. For the static limit γ=γ(0;0,0,0) we obtain γ=86.5 a.u. This value agrees very well with a recent experimental value of 75 a.u. <γ<93 a.u. obtained by Shelton and Lu [Phys. Rev. A 37, 3813 (1988)]. The results for the Kerr hyperpolarizability γ(ω;0,0,ω)=${\gamma }^{\mathrm{Kerr}}$ provide an estimate of the dispersion effects. Approximating our results with the formula ${\gamma }^{\mathrm{Kerr}=\gamma (1+\mathrm{A}{\omega }_L^2}$), where for the Kerr effect ${\omega }_L^2$=2${\omega }^2$, we find A≊0.50×${10}^{\mathrm{-}10}$ ${\mathrm{cm}}^2$.