We present a new paper on Density Functional Polarization Theory (DFPT). This theory is an extension of Time-Dependent-DFT where the exchange correlation functional depends not only from the density but also from the polarization P. Thanks to this explicit dependence on P it is possible solve different problems of TD-DFT in periodic systems with a simple and fast functional without introducing divergences in the theory. Different ways to derive parameters that enter in the functional are presented in the paper and the corresponding functionals are tested again linear and non-linear response of bulk semi-conductors.

**References:**

- Dielectrics in a time-dependent electric field: a real-time approach based on density-polarization functional theory

M. Grüning, D. Sangalli, C. Attaccalite

http://arxiv.org/abs/1604.04540 - Performance of polarisation functionals for linear and nonlinear optical properties of bulk zinc chalcogenides ZnX (X= S, Se, and Te)

M. Grüning, C. Attaccalite

Physical Chemistry Chemical Physics (2016)