No abstract

No abstract

Using the Hartree-Fock and single configuration interaction model in conjunction with the local field method, the dielectric tensor, refractive index, circular dichroism, birefringence coefficient and the effects of spatial dispersion on the spectrum of the transverse normal polariton waves of the simple cubic phase of the C 60 crystal are calculated. Our results on magneto-optical circular dichroism in the energy range 3-4 eV almost reproduces the reported experimental results. Also, our results on the effect of spatial dispersion, compared with the non-dispersive case, indicate that the first branch of the transverse normal polariton in the C 60 crystal is due to the coupling of the second excitonic state of the C 60 molecule with the electromagnetic field and the first excitonic state has very weak coupling.

The Hartree-Fock (HF) approximation and the Single-excitation configuration interaction (single-CI) method are used, with sum-over-state (SOS) approach, in order to determine the static (x ¼ 0) and frequency dependent linear and non linear optical (NLO) properties of the M @ C 60 endohedrals (M ¼ Cs, Li, and Na). We discuss the effects of displacement, movement direction, and type of atom on the (hyper) polarizability of the M at C 60 endohedrals. A HF-single-CI model yields the (hyper) polarizability magnitudes and spectra, which are in agreement with experiment. Our results indicate that the movement of the atom (M) effect on the NLO spectra of M @ C 60 endohedrals is dramatic. These results may provide new means to design some new types of NLO materials.