Calculations of hyperpolarizability of fullerene C₆₀ anions

In the framework of the semi-empirical version of TDHF approach, the spectral parameters, linear and higher polarizabilities (in particular, for THG and EFISH) are calculated for free C₆₀ molecule and crystal, and for closed-shell anions (C₆₀)^-2, (C₆₀) ^-4, (C₆₀)^-6 in fullerides. It is demonstrated that the direct calculation of polarizability for the neutral molecule in crystals and similar calculation by means of the Lorentz factors gives the equivalent results while for HP the direct calculation includes higher field effects resulting in the approximately 5% increase of HP as compared to the Lorentz type calculation.