## UC Berkeley / Lawrence Berkeley Laboratory

#### Efficient implementation of time-dependent density-functional theory to treat non-linear dynamical processes in molecular nanostructures and solids

**Angel Rubio, Universitdad de Pais Vasco**

##### September 3rd, 2014 at 3:30PM–4:30PM in 939 Evans Hall [Map]

In the present talk I will review the recent advances in algorithm development and numerical implementation of a real-space scheme to solve the
time-dependent Kohn-Sham equations of time-dependent density functional theory. I will illustrate the perfromance towards petaflop computing and discuss the open
problems from both physical concepts as well as algorithm development. A review of the recent work to describe spectroscopic properties of different semiconducting
nanostructures and biomolecules will be discussed including both the linear and non-linear response regimes.

I will describe a new method to address the electron-ion dynamics within the Ehrenfest scheme where no explicit orthogonalization is necessary and we
can increase the time step while keeping the system close to the adiabatic dynamics. The method is easily implemented and scales very well with the system
size. Applications to the excited state dynamics in some organic molecules will be used as test cases to illustrate the performance of the approach. In particular we will show
the effect of electron-hole attraction in those systems. Pros and cons of present functionals will be highlighted and provide insight in how to overcome those
limitations by using many-body perturbation theory.

The goal of the group activities in the long-run is to provide a detailed, efficient, and at the same time accurate microscopic approach for the ab-initio description and control of the dynamics of decoherence and dissipation in quantum many-body systems. With the help of quantum optimal control (QOC) theory and the mastery over spectroscopy we could direct the movement of electrons, selectively trigger chemical reactions and processes, and create new materials.
The present developments constitute a basic ingredient for the development of the European Theoretical
Spectroscopy Facility (ETSF, http://etsf.eu) as well as its Vicepresindency for Scientific development in San Sebastian.