Dipole–quadrupole and dipole–octopole polarizability for CH4 and CF4

We have relied on accurate finite-field self-consistent field and coupled-cluster calculations to obtain for the dipole–quadrupole and dipole–octopole polarizability of CH4 the values A=9.01 e2a30Eh−1 and E=−18.9 e2a40Eh−1. For CF4 our best values combine finite-field self-consistent field and complete fourth-order perturbation theory calculations and they are A=12.4 e2a30Eh−1 and E=−27.8 e2a40Eh−1.