Recent progress in the computation of non linear optical properties of chiral systems

An account is given of the recent progresses observed in the theoretical and computational prediction of non linear frequency-dependent properties of systems involving molecules with chiral centers or immersed in a chiral environment. The discussion will cover the analysis of the two-photon circular dichroic response of helicenes, typical prototypes of structurally chiral systems; of R-(+)-3 methyl cyclopentanone a likely candidate for a first direct measurement of two-photon circular dichroism; and more generally of the whole class of natural essential aminoacids. Particular attention will be given to the effects of the environment and of conformational flexibility. A second topic will involve a report on the conclusions of extended ab initio studies of magnetochiral birefringence and of Faraday classical (and optical) rotation, two examples of how non-linear optical properties can be a challenging subject where computational science can play a fundamental predictive and rationalizing role.