## Time-dependent quantum chemistry for high-harmonic generation spectroscopy

E. Coccia

Laboratoire de Chimie Théorique, Université Pierre et Marie Curie et CNRS, Paris, France et Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila, via Vetoio, L'Aquila, Italie.

coccia@lct.jussieu.fr

Mercredi 22 Juin 2016, 11^{h}00

bibliothèque LCT, tour 12 - 13, 4e étage

We explore the computation of high-harmonic generation (HHG) spectra by means of Gaussian basis sets by propagating the time-dependent Schrödinger equation in the TD-CIS framework. We investigate the efficiency of Gaussian functions specifically designed for the description of the continuum proposed by Kaufmann et al. [J. Phys. B 22, 2223 (1989)]. We assess the range of applicability of this approach by studying the hydrogen atom, i.e. the simplest atom for which reference calculations on a grid can be performed [1]. The efficiency of this kind of basis set is compared to the use of ghost atoms surrounding the hydrogen for computing the HHG spectrum [2]. Moreover, we propose an alternative way to compute finite lifetimes for modeling the electron loss due to ionization, based on the fit of the radial profile of continuum wave functions [3]. Preliminary results on the HHG spectrum of the He atom and of the H_{2} molecule are also shown.

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[1] E. Coccia, B. Mussard, M. Lebeye, J. Caillet, R. Taïeb, J. Toulouse, E. Luppi *Int. J. Quant. Chem.* **116** 1120 (2016).

[2] E. Coccia, E. Luppi *Theor. Chem. Acc.* **135** 43 (2016).

[3] E. Coccia, R. Assaraf, E. Luppi, J. Toulouse, in preparation.