Full-CI calculation of imaginary frequency-dependent dipole–quadrupole polarizabilities of ground state LiH and the C7 dispersion coefficients of LiH–LiH

Full-CI calculations of frequency-dependent dipole and dipole–quadrupole polarizabilities of ground state LiH have been performed in the imaginary frequency range 0–56 a.u. using a set of 58 Gaussian type orbitals (GTOs) giving a Full-CI dimension of about 700.000 determinants in each symmetry-adapted subspace. A 16-point Gauss–Legendre quadrature of the Casimir–Polder formula over imaginary frequencies allows calculation of the dipole–quadrupole dispersion constants for the LiH–LiH homodimer, from which C7 dispersion coefficients are derived for the first time.