An efficient method for calculating dynamical hyperpolarizabilities using real-time time-dependent density functional theory

作者：Ding Feizhi; Van Kuiken Benjamin E; Eichinger Bruce E; Li Xiaosong^*

来源：Journal of Chemical Physics, 2013, 138(6): 064104.

DOI：10.1063/1.4790583

In this paper we present a time-domain time-dependent density functional theory (TDDFT) approach to calculate frequency-dependent polarizability and hyperpolarizabilities. In this approach, the electronic degrees of freedom are propagated within the density matrix based TDDFT framework using the efficient modified midpoint and unitary transformation algorithm. We use monochromatic waves as external perturbations and apply the finite field method to extract various orders of the time-dependent dipole moment. By fitting each order of time-dependent dipole to sinusoidal waves with harmonic frequencies, one can obtain the corresponding (hyper) polarizability tensors. This approach avoids explicit Fourier transform and therefore does not require long simulation time. The method is illustrated with application to the optically active organic molecule para-nitroaniline, of which the frequency-dependent polarizability alpha(-omega; omega), second-harmonic generation beta(-2 omega; omega, omega), optical rectification beta(0; -omega, omega), third-harmonic generation gamma(-3 omega; omega, omega, omega), and degenerate four-wave mixing gamma(-omega; omega, omega, -omega) are calculated.

• 出版日期2013-2-14