C7 long-range dispersion coefficients for LiH–LiH are evaluated from Full-CI calculations of frequency-dependent dipole and dipole–quadrupole polarizabilities of ground state LiH at a few selected imaginary frequencies. The elementary dispersion constants are evaluated analytically from the Casimir–Polder integral using a recently proposed interpolation technique in its 2-term form which requires knowledge of just four polarizability values. The enlarged basis of 109 GTOs used in this work improves upon earlier results obtained by use of the smaller 58 GTOs basis set.