Av. Shtoff et al., Ab initio calculations of the second dynamic hyperpolarizability of LiH bymeans of Floquet theory approach, EUR PHY J D, 15(2), 2001, pp. 199-208
Floquet theory is used to describe the response of a molecule to applied ra
diation electric field. The method of ab initio calculation of frequency de
pendent (hyper)polarizabilities based on combination of perturbation theory
with the finite field method has been developed. Electron correlation is t
aken into account by means of the CIPSI algorithm. The total wave function
expansion involves spectral, pseudospectral states and polynomial terms. Th
e developed approach is applied to the calculation of the second hyperpolar
izability of the lithium hydride molecule subjected to the superposition of
harmonic and static electric fields. The method can be used to calculate t
he higher order nonlinear properties of molecules.